When we get a port status change event, we need to figure out what type of
port it came from: a USB 3.0 port, or a USB 2.0/1.1 port. We can't know
which usb_hcd to use until that point, so hcd will be NULL for part of the
function. Unfortunately, if any of the sanity checks fail, we'll jump to
the cleanup label before hcd is set to a valid pointer, and then we'll
attempt to tell the USB core to kick the hcd, which is NULL.
Skip kicking the roothub if the sanity checks fail.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
The logic of the handling Missed Service Error Events was pretty
confusing as we were checking the same condition several times.
In addition, it caused compiler warning since the compiler could
not figure out that event_trb is actually unused in case we are
skipping current TD.
Fix that by rearranging "skip" condition checks, and factor out
skip_isoc_td() so that it is called explicitly.
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Remove 'inline' markings from file-local functions and let compiler
do its job and inline what makes sense for given architecture.
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
There were some places that compared port_speed == -1 where port_speed
is a u8. This doesn't work unless we cast the -1 to u8. Some places
did it correctly.
Instead of using -1 directly, I've created a DUPLICATE_ENTRY define
which does the cast and is more descriptive as well.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
* 'usb-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (172 commits)
USB: Add support for SuperSpeed isoc endpoints
xhci: Clean up cycle bit math used during stalls.
xhci: Fix cycle bit calculation during stall handling.
xhci: Update internal dequeue pointers after stalls.
USB: Disable auto-suspend for USB 3.0 hubs.
USB: Remove bogus USB_PORT_STAT_SUPER_SPEED symbol.
xhci: Return canceled URBs immediately when host is halted.
xhci: Fixes for suspend/resume of shared HCDs.
xhci: Fix re-init on power loss after resume.
xhci: Make roothub functions deal with device removal.
xhci: Limit roothub ports to 15 USB3 & 31 USB2 ports.
xhci: Return a USB 3.0 hub descriptor for USB3 roothub.
xhci: Register second xHCI roothub.
xhci: Change xhci_find_slot_id_by_port() API.
xhci: Refactor bus suspend state into a struct.
xhci: Index with a port array instead of PORTSC addresses.
USB: Set usb_hcd->state and flags for shared roothubs.
usb: Make core allocate resources per PCI-device.
usb: Store bus type in usb_hcd, not in driver flags.
usb: Change usb_hcd->bandwidth_mutex to a pointer.
...
Use XOR to invert the cycle bit, instead of a more complicated
calculation. Eliminate a check for the link TRB type in find_trb_seg().
We know that there will always be a link TRB at the end of a segment, so
xhci_segment->trbs[TRBS_PER_SEGMENT - 1] will always have a link TRB type.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Takashi Iwai <tiwai@suse.de>
When an endpoint stalls, we need to update the xHCI host's internal
dequeue pointer to move it past the stalled transfer. This includes
updating the cycle bit (TRB ownership bit) if we have moved the dequeue
pointer past a link TRB with the toggle cycle bit set.
When we're trying to find the new dequeue segment, find_trb_seg() is
supposed to keep track of whether we've passed any link TRBs with the
toggle cycle bit set. However, this while loop's body
while (cur_seg->trbs > trb ||
&cur_seg->trbs[TRBS_PER_SEGMENT - 1] < trb) {
Will never get executed if the ring only contains one segment.
find_trb_seg() will return immediately, without updating the new cycle
bit. Since find_trb_seg() has no idea where in the segment the TD that
stalled was, make the caller, xhci_find_new_dequeue_state(), check for
this special case and update the cycle bit accordingly.
This patch should be queued to kernels all the way back to 2.6.31.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Takashi Iwai <tiwai@suse.de>
Cc: stable@kernel.org
When an endpoint stalls, the xHCI driver must move the endpoint ring's
dequeue pointer past the stalled transfer. To do that, the driver issues
a Set TR Dequeue Pointer command, which will complete some time later.
Takashi was having issues with USB 1.1 audio devices that stalled, and his
analysis of the code was that the old code would not update the xHCI
driver's ring dequeue pointer after the command completes. However, the
dequeue pointer is set in xhci_find_new_dequeue_state(), just before the
set command is issued to the hardware.
Setting the dequeue pointer before the Set TR Dequeue Pointer command
completes is a dangerous thing to do, since the xHCI hardware can fail the
command. Instead, store the new dequeue pointer in the xhci_virt_ep
structure, and update the ring's dequeue pointer when the Set TR dequeue
pointer command completes.
While we're at it, make sure we can't queue another Set TR Dequeue Command
while the first one is still being processed. This just won't work with
the internal xHCI state code. I'm still not sure if this is the right
thing to do, since we might have a case where a driver queues multiple
URBs to a control ring, one of the URBs Stalls, and then the driver tries
to cancel the second URB. There may be a race condition there where the
xHCI driver might try to issue multiple Set TR Dequeue Pointer commands,
but I would have to think very hard about how the Stop Endpoint and
cancellation code works. Keep the fix simple until when/if we run into
that case.
This patch should be queued to kernels all the way back to 2.6.31.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Takashi Iwai <tiwai@suse.de>
Cc: stable@kernel.org
Make sure the HCD_FLAG_HW_ACCESSIBLE flag is mirrored by both roothubs,
since it refers to whether the shared hardware is accessible. Make sure
each bus is marked as suspended by setting usb_hcd->state to
HC_STATE_SUSPENDED when the PCI host controller is resumed.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
This patch changes the xHCI driver to allocate two roothubs. This touches
the driver initialization and shutdown paths, roothub emulation code, and
port status change event handlers. This is a rather large patch, but it
can't be broken up, or it would break git-bisect.
Make the xHCI driver register its own PCI probe function. This will call
the USB core to create the USB 2.0 roothub, and then create the USB 3.0
roothub. This gets the code for registering a shared roothub out of the
USB core, and allows other HCDs later to decide if and how many shared
roothubs they want to allocate.
Make sure the xHCI's reset method marks the xHCI host controller's primary
roothub as the USB 2.0 roothub. This ensures that the high speed bus will
be processed first when the PCI device is resumed, and any USB 3.0 devices
that have migrated over to high speed will migrate back after being reset.
This ensures that USB persist works with these odd devices.
The reset method will also mark the xHCI USB2 roothub as having an
integrated TT. Like EHCI host controllers with a "rate matching hub" the
xHCI USB 2.0 roothub doesn't have an OHCI or UHCI companion controller.
It doesn't really have a TT, but we'll lie and say it has an integrated
TT. We need to do this because the USB core will reject LS/FS devices
under a HS hub without a TT.
Other details:
-------------
The roothub emulation code is changed to return the correct number of
ports for the two roothubs. For the USB 3.0 roothub, it only reports the
USB 3.0 ports. For the USB 2.0 roothub, it reports all the LS/FS/HS
ports. The code to disable a port now checks the speed of the roothub,
and refuses to disable SuperSpeed ports under the USB 3.0 roothub.
The code for initializing a new device context must be changed to set the
proper roothub port number. Since we've split the xHCI host into two
roothubs, we can't just use the port number in the ancestor hub. Instead,
we loop through the array of hardware port status register speeds and find
the Nth port with a similar speed.
The port status change event handler is updated to figure out whether the
port that reported the change is a USB 3.0 port, or a non-SuperSpeed port.
Once it figures out the port speed, it kicks the proper roothub.
The function to find a slot ID based on the port index is updated to take
into account that the two roothubs will have over-lapping port indexes.
It checks that the virtual device with a matching port index is the same
speed as the passed in roothub.
There's also changes to the driver initialization and shutdown paths:
1. Make sure that the xhci_hcd pointer is shared across the two
usb_hcd structures. The xhci_hcd pointer is allocated and the
registers are mapped in when xhci_pci_setup() is called with the
primary HCD. When xhci_pci_setup() is called with the non-primary
HCD, the xhci_hcd pointer is stored.
2. Make sure to set the sg_tablesize for both usb_hcd structures. Set
the PCI DMA mask for the non-primary HCD to allow for 64-bit or 32-bit
DMA. (The PCI DMA mask is set from the primary HCD further down in
the xhci_pci_setup() function.)
3. Ensure that the host controller doesn't start kicking khubd in
response to port status changes before both usb_hcd structures are
registered. xhci_run() only starts the xHC running once it has been
called with the non-primary roothub. Similarly, the xhci_stop()
function only halts the host controller when it is called with the
non-primary HCD. Then on the second call, it resets and cleans up the
MSI-X irqs.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
xhci_find_slot_id_by_port() tries to map the port index to the slot ID for
the USB device. In the future, there will be two xHCI roothubs, and their
port indices will overlap. Therefore, xhci_find_slot_id_by_port() will
need to use information in the roothub's usb_hcd structure to map the port
index and roothub speed to the right slot ID.
Add a new parameter to xhci_find_slot_id_by_port(), in order to pass in
the roothub's usb_hcd structure.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
There are several variables in the xhci_hcd structure that are related to
bus suspend and resume state. There are a couple different port status
arrays that are accessed by port index. Move those variables into a
separate structure, xhci_bus_state. Stash that structure in xhci_hcd.
When we have two roothhubs that can be suspended and resumed separately,
we can have two xhci_bus_states, and index into the port arrays in each
structure with the fake roothub port index (not the real hardware port
index).
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
In the upcoming patches, the roothub emulation code will need to return
port status and port change buffers based on whether they are called with
the xHCI USB 2.0 or USB 3.0 roothub. To facilitate that, make the roothub
code index into an array of port addresses with wIndex, rather than
calculating the address using the offset and the address of the PORTSC
registers. Later we can set the port array to be the array of USB 3.0
port addresses, or the USB 2.0 port addresses, depending on the roothub
passed in.
Create a temporary (statically sized) port array and fill it in with both
USB 3.0 and USB 2.0 port addresses. This is inefficient to do for every
roothub call, but this is needed for git bisect compatibility. The
temporary port array will be deleted in a subsequent patch.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
The hcd->flags are in a sorry state. Some of them are clearly specific to
the particular roothub (HCD_POLL_RH, HCD_POLL_PENDING, and
HCD_WAKEUP_PENDING), but some flags are related to PCI device state
(HCD_HW_ACCESSIBLE and HCD_SAW_IRQ). This is an issue when one PCI device
can have two roothubs that share the same IRQ line and hardware.
Make sure to set HCD_FLAG_SAW_IRQ for both roothubs when an interrupt is
serviced, or an URB is unlinked without an interrupt. (We can't tell if
the host actually serviced an interrupt for a particular bus, but we can
tell it serviced some interrupt.)
HCD_HW_ACCESSIBLE is set once by usb_add_hcd(), which is set for both
roothubs as they are added, so it doesn't need to be modified.
HCD_POLL_RH and HCD_POLL_PENDING are only checked by the USB core, and
they are never set by the xHCI driver, since the roothub never needs to be
polled.
The usb_hcd's state field is a similar mess. Sometimes the state applies
to the underlying hardware: HC_STATE_HALT, HC_STATE_RUNNING, and
HC_STATE_QUIESCING. But sometimes the state refers to the roothub state:
HC_STATE_RESUMING and HC_STATE_SUSPENDED.
Alan Stern recently made the USB core not rely on the hcd->state variable.
Internally, the xHCI driver still checks for HC_STATE_SUSPENDED, so leave
that code in. Remove all references to HC_STATE_HALT, since the xHCI
driver only sets and doesn't test those variables. We still have to set
HC_STATE_RUNNING, since Alan's patch has a bug that means the roothub
won't get registered if we don't set that.
Alan's patch made the USB core check a different variable when trying to
determine whether to suspend a roothub. The xHCI host has a split
roothub, where two buses are registered for one PCI device. Each bus in
the xHCI split roothub can be suspended separately, but both buses must be
suspended before the PCI device can be suspended. Therefore, make sure
that the USB core checks HCD_RH_RUNNING() for both roothubs before
suspending the PCI host.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Make sure to call into the USB core's link, unlink, and giveback URB
functions with the usb_hcd pointer found by using urb->dev->bus. This
will avoid confusion later, when the xHCI driver will deal with URBs from
two separate buses (the USB 3.0 roothub and the faked USB 2.0 roothub).
Assume xhci_urb_dequeue() will be called with the proper usb_hcd.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
The xHCI driver doesn't ever test hcd->state for HC_STATE_HALT. The USB
core recently stopped using it internally, so there's no point in setting
it in the driver. We still need to set HC_STATE_RUNNING in order to make
it past the USB core's hcd->state check in register_roothub().
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
The xhci_bus_suspend() and xhci_bus_resume() functions are a bit hard to
read, because they have an ambiguously named variable "port". Rename it
to "port_index". Introduce a new temporary variable, "max_ports" that
holds the maximum number of roothub ports the host controller supports.
This will reduce the number of register reads, and make it easy to change
the maximum number of ports when there are two roothubs.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
The test of placing a number of command no-ops on the command ring and
counting the number of no-op events that were generated was only used
during the initial xHCI driver bring up. This test is no longer used, so
delete it.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
The expression
while (running_total < sg_dma_len(sg))
does not take into account that the remaining data length can be less
than sg_dma_len(sg). In that case, running_total can end up being
greater than the total data length, so an extra TRB is counted.
Changing the expression to
while (running_total < sg_dma_len(sg) && running_total < temp)
fixes that.
This patch should be queued for stable kernels back to 2.6.31.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
Calculations like
running_total = TRB_MAX_BUFF_SIZE -
(sg_dma_address(sg) & (TRB_MAX_BUFF_SIZE - 1));
if (running_total != 0)
num_trbs++;
are incorrect, because running_total can never be zero, so the if()
expression will never be true. I think the intention was that
running_total be in the range of 0 to TRB_MAX_BUFF_SIZE-1, not 1
to TRB_MAX_BUFF_SIZE. So adding a
running_total &= TRB_MAX_BUFF_SIZE - 1;
fixes the problem.
This patch should be queued for stable kernels back to 2.6.31.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
This makes it easier to spot some problems, which will be fixed by the
next patch in the series. Also change dev_dbg to dev_err in
check_trb_math(), so any math errors will be visible even when running
with debug disabled.
Note: This patch changes the expressions containing
"((1 << TRB_MAX_BUFF_SHIFT) - 1)" to use the equivalent
"(TRB_MAX_BUFF_SIZE - 1)". No change in behavior is intended for
those expressions.
This patch should be queued for stable kernels back to 2.6.31.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
Change the BUGs in xhci_find_new_dequeue_state() to WARN_ONs, to avoid
bringing down the box if one of them is hit
This patch should be queued for stable kernels back to 2.6.31.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
The unused space in the doorbell is now marked as RsvdZ, not RsvdP, so
we can avoid reading the doorbell before writing it.
Update the doorbell-related defines to produce the entire doorbell value
from a single macro. Document the doorbell format in a comment.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
dev_dbg() is used to print ordinary transfer messages in xhci-ring.c.
System log messages will be flushed if CONFIG_USB_DEBUG is set. Replace the
dev_dbg() with xhci_dbg().
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
giveback_first_trb() controls the cycle bit set of the start_trb, to ensure
that the start_trb is written last and the host controller will receive a
whole td at a time.
However, if the ring is wrapped and cycle bit is toggled to zero, then
giveback_first_trb() will be of no effect. In this case, set the cycle bit of
start_trb to 1 at the beginning and clear it in giveback_first_trb().
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Parameter *td is not used in giveback_first_trb(). Remove it.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Fix the more_trbs_coming field of queue_trb() in isoc transfer.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
The original code that resumed the USB bus on a port status change would
only do so when there was a device connected to the port. If a device was
just disconnected, the event would be queued for khubd, but khubd wouldn't
run. That would leave the connect status change (CSC) bit set.
If a USB device was plugged into that same port, the xHCI host controller
would set the current connect status (CCS) bit. But since the CSC bit was
already set, it would not generate an interrupt for a port status change
event. That would mean the user could "Safely Remove" a device, have the
bus suspend, disconnect the device, re-plug it in, and then the device
would never be enumerated.
Plugging in a different device on another port would cause the bus to
resume, and khubd would notice the re-connected device. Running lsusb
would also resume the bus, leading users to report the problem "went away"
when using diagnostic tools.
The solution is to resume the bus when a port status change event is
received, regardless of the port status.
Thank you very much to Maddog for helping me track down this Heisenbug.
This patch should be queued for the 2.6.37 stable tree.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: Jon 'maddog' Hall <maddog@li.org>
Tested-by: Andiry Xu <andiry.xu@amd.com>
Cc: stable@kernel.org
If the xHCI host controller shares an interrupt line with another device,
the xHCI driver needs to check if the interrupt was generated by its
hardware. Unfortunately, the user will see a ton of "Spurious interrupt."
lines if the other hardware interrupts often. Lawrence found his dmesg
output cluttered with this output when the xHCI host shared an interrupt
with his i915 hardware.
Remove the warning, as sharing an interrupt is a normal thing.
This should be applied to the 2.6.36 stable tree.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: Lawrence Rust <lvr@softsystem.co.uk>
Cc: stable@kernel.org
This commit implements port remote wakeup.
When a port is in U3 state and resume signaling is detected from a device,
the port transitions to the Resume state, and the xHC generates a Port Status
Change Event.
For USB3 port, software write a '0' to the PLS field to complete the resume
signaling. For USB2 port, the resume should be signaling for at least 20ms,
irq handler set a timer for port remote wakeup, and then finishes process in
hub_control GetPortStatus.
Some codes are borrowed from EHCI code.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add software trigger USB device suspend resume function hook.
Do port suspend & resume in terms of xHCI spec.
Port Suspend:
Stop all endpoints via Stop Endpoint Command with Suspend (SP) flag set.
Place individual ports into suspend mode by writing '3' for Port Link State
(PLS) field into PORTSC register. This can only be done when the port is in
Enabled state. When writing, the Port Link State Write Strobe (LWS) bit shall
be set to '1'.
Allocate an xhci_command and stash it in xhci_virt_device to wait completion for
the last Stop Endpoint Command. Use the Suspend bit in TRB to indicate the Stop
Endpoint Command is for port suspend. Based on Sarah's suggestion.
Port Resume:
Write '0' in PLS field, device will transition to running state.
Ring an endpoints' doorbell to restart it.
Ref: USB device remote wake need another patch to implement. For details of
how USB subsystem do power management, please see:
Documentation/usb/power-management.txt
Signed-off-by: Crane Cai <crane.cai@amd.com>
Signed-off-by: Libin Yang <libin.yang@amd.com>
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes a isoc transfer bug reported by Sander Eikelenboom.
When ep->skip is set, endpoint ring dequeue pointer should be updated
when processed every missed td. Although ring dequeue pointer will also
be updated when ep->skip is clear, leave it intact during missed tds
processing may cause two issues:
1). If the very next valid transfer following missed tds is a short
transfer, its actual_length will be miscalculated;
2). If there are too many missed tds during transfer, new inserted tds
may found the transfer ring full and urb enqueue fails.
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Tested-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The code to increment the TRB pointer has a slight ambiguity that could
lead to a bug on different compilers. The ANSI C specification does not
specify the precedence of the assignment operator over the postfix
operator. gcc 4.4 produced the correct code (increment the pointer and
assign the value), but a MIPS compiler that one of John's clients used
assigned the old (unincremented) value.
Remove the unnecessary assignment to make all compilers produce the
correct assembly.
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
To tell the host controller that there are transfers on the endpoint
rings, we need to ring the endpoint doorbell. This is a PCI MMIO write,
which can be delayed until another register read is queued.
The previous code would flush the doorbell write by reading the doorbell
register after the write. This may take time, and it's not necessary to
force the host controller to know about the transfers right away. Don't
flush the doorbell register writes.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The interrupter register set includes a register that says whether interrupts
are pending for each event ring (the IP bit). Each MSI-X vector will get its
own interrupter set with separate IP bits. The status register includes an
"Event Interrupt (EINT)" bit that is set when an IP bit is set in any of the
interrupters.
When PCI interrupts are used, the EINT bit exactly mirrors the IP bit in the
single interrupter set, and it is a waste of time to check both registers when
trying to figure out if the xHC interrupted or another device on the shared IRQ
line interrupted. Only check the IP bit to reduce register reads.
The IP bit is automatically cleared by the xHC when MSI or MSI-X is enabled. It
doesn't make sense to read that register to check for shared interrupts (since
MSI and MSI-X aren't shared). It also doesn't make sense to write to that
register to clear the IP bit, since it is cleared by the hardware.
We can tell whether MSI or MSI-X is enabled by looking at the irq number in
hcd->irq. If it's -1, we know MSI or MSI-X is enabled.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Now that the event handler functions no longer use xhci_set_hc_event_deq()
to update the event ring dequeue pointer, that function is not used by
anything in xhci-ring.c. Move that function into xhci-mem.c and make it
static.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The xHCI specification suggests that writing the hardware event ring dequeue
pointer register too often can be an expensive operation for the xHCI hardware
to manage. It suggests minimizing the number of writes to that register.
Originally, the driver wrote the event ring dequeue pointer after each
event was processed. Depending on how the event ring moderation register
is set up and how fast the transfers are completing, there may be several
events processed for each interrupt. This patch makes the hardware event
ring dequeue pointer be written only once per interrupt.
Make the transfer event handler and port status event handler only write
the software event ring dequeue pointer. Move the updating of the
hardware event ring dequeue pointer into the interrupt function. Move the
contents of xhci_set_hc_event_deq() into the interrupt handler. The
interrupt handler must clear the event handler busy flag, so it might as
well also write the dequeue pointer to the same register. This eliminates
two 32-bit PCI reads and two 32-bit PCI writes.
Reported-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
xhci_handle_event() is now only called from within xhci-ring.c, so make it
static.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Remove a duplicate register read of the interrupt pending register from
xhci_irq(). Also, remove waiting on the posted write of that register.
The host will see it eventually. It will probably read the register
itself before deciding whether to interrupt the system again, forcing the
posted write to complete.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When we move xhci_work() into xhci_irq(), we don't need to read the operational
register status field twice.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Most of the work for interrupt handling is done in xhci-ring.c, so it makes
sense to move the functions that are first called when an interrupt happens
(xhci_irq() or xhci_msi_irq()) into xhci-ring.c, so that the compiler can better
optimize them.
Shorten some lines to make it pass checkpatch.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
I've been using perf to measure the top symbols while transferring 1GB of data
on a USB 3.0 drive with dd. This is using the raw disk with /dev/sdb, with a
block size of 1K.
During performance testing, the top symbol was xhci_triad_to_transfer_ring(), a
function that should return immediately if streams are not enabled for an
endpoint. It turned out that the functions to find the endpoint ring was
defined in xhci-mem.c and used in xhci-ring.c and xhci-hcd.c. I moved a copy of
xhci_triad_to_transfer_ring() and xhci_urb_to_transfer_ring() into xhci-ring.c
and declared them static. I also made a static version of
xhci_urb_to_transfer_ring() in xhci.c.
This improved throughput on a 1GB read of the raw disk with dd from
186MB/s to 195MB/s, and perf reported sampling the xhci_triad_to_transfer_ring()
0.06% of the time, rather than 9.26% of the time.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch implements isochronous urb enqueue and interrupt handler part.
When an isochronous urb is passed to xHCI driver, first check the transfer
ring to guarantee there is enough room for the whole urb. Then update the
start_frame and interval field of the urb. Always assume URB_ISO_ASAP
is set, and never use urb->start_frame as input.
The number of isoc TDs is equal to urb->number_of_packets. One isoc TD is
consumed every Interval. Each isoc TD consists of an Isoch TRB chained to
zero or more Normal TRBs.
Call prepare_transfer for each TD to do initialization; then calculate the
number of TRBs needed for each TD. If the data required by an isoc TD is
physically contiguous (not crosses a page boundary), then only one isoc TRB
is needed; otherwise one or more additional normal TRB shall be chained to
the isoc TRB by the host.
Set TRB_IOC to the last TRB of each isoc TD. Do not ring endpoint doorbell
to start xHC procession until all the TDs are inserted to the endpoint
transer ring.
In irq handler, update urb status and actual_length, increase
urb_priv->td_cnt. When all the TDs are completed(td_cnt is equal to
urb_priv->length), giveback the urb to usbcore.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add urb_priv data structure to xHCI driver. This structure allows multiple
xhci TDs to be linked to one urb, which is essential for isochronous
transfer. For non-isochronous urb, only one TD is needed for one urb;
for isochronous urb, the TD number for the urb is equal to
urb->number_of_packets.
The length field of urb_priv indicates the number of TDs in the urb.
The td_cnt field indicates the number of TDs already processed by xHC.
When td_cnt matches length, the urb can be given back to usbcore.
When an urb is dequeued or cancelled, add all the unprocessed TDs to the
endpoint's cancelled_td_list. When process a cancelled TD, increase
td_cnt field. When td_cnt equals urb_priv->length, giveback the
cancelled urb.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch adds mechanism to process Missed Service Error Event.
Sometimes the xHC is unable to process the isoc TDs in time, it will
generate Missed Service Error Event. In this case some TDs on the ring are
not processed and missed. When encounter a Missed Servce Error Event, set
the skip flag of the ep, and process the missed TDs until reach the next
processed TD, then clear the skip flag.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch adds new cases to trb_comp_code switch, and moves
the switch judgment ahead of fetching td.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch moves the bulk and interrupt td processing part in
handle_tx_event() into a separate function process_bulk_intr_td().
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch moves the ctrl td processing part in handle_tx_event()
into a separate function process_ctrl_td().
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch moves the td universal processing part in handle_tx_event()
into a separate function finish_td().
if finish_td() returns 1, it indicates the urb can be given back.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Commit 6c12db90f1 also seems to have
introduced a bug that is triggered when the command ring is about to wrap.
The inc_enq() function will not have moved the enqueue pointer past the
link TRB. It is supposed to be moved past the link TRB in prepare_ring(),
which should be called before a TD is enqueued. However, the
queue_command() function never calls the prepare_ring() function because
prepare_ring() is only supposed to be used for endpoint rings. That means
the enqueue pointer will not be moved past the link TRB, and will get
overwritten.
The fix is to make queue_command() call prepare_ring() with a fake
endpoint status (set to running). Then the enqueue pointer will get moved
past the link TRB.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Commit 6c12db90f1 introduced a bug for
control transfers. The patch was supposed to change when the link TRBs at
the end of each ring segment were given to the hardware. If a transfer
descriptor (TD) ended just before the link TRB, the code wouldn't give
back the link TRB to the hardware; instead it would be given back in
prepare_ring() just before the next TD was enqueued at the top of the
ring.
Unfortunately, the code relied on checking the chain bit of the TRB to
determine whether the TD ended just before the link TRB. It assumed that
the ring enqueuing code would call prepare_ring() before enqueuing the
next TD. However, control transfers are made of multiple TDs, and
prepare_ring() is only called once before enqueuing two or three TDs.
If the first or second TD of the control transfer ended just before the
link TRB, then the code in inc_enq() would not move the enqueue pointer
past the link TRB, and the link TRB would get overwritten. This would
cause the xHCI driver to start writing to memory past the ring segment,
and eventually the system would crash or hang.
The fix is to add a flag to inc_enq() that says whether the caller will
enqueue more TDs before calling prepare_ring(). If the chain bit is
cleared (meaning this is the last TRB in a TD), and the caller will not
enqueue more TDs, then we defer giving back the link TRB.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The NEC xHCI host controller firmware version can be found by putting a
vendor-specific command on the command ring and extracting the BCD
encoded-version out of the vendor-specific event TRB.
The firmware version debug line in dmesg will look like:
xhci_hcd 0000:05:00.0: NEC firmware version 30.21
(NEC merged with Renesas Technologies and became Renesas Electronics on
April 1, 2010. I have their OK to merge this vendor-specific code.)
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Satoshi Otani <satoshi.otani.xm@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Change transfer ring behavior to not follow/activate link TRBs
until active TRBs are queued after it. This change affects
the behavior when a TD ends just before a link TRB.
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
After using state stored in xhci_virt_ep to clean up a stalled endpoint,
be sure to set the stalled stream ID back to 0.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Change the type of the URB's 'sg' pointer from a usb_sg_request to
a scatterlist. This allows drivers to submit scatter-gather lists
without using the usb_sg_wait() interface. It has the added benefit
of removing the typecasts that were added as part of patch as1368 (and
slightly decreasing the number of pointer dereferences).
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix usb sparse warnings:
drivers/usb/host/isp1362-hcd.c:2220:50: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:43:24: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:49:24: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:161:24: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:198:16: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:319:31: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:1231:33: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-pci.c:177:23: warning: non-ANSI function declaration of function 'xhci_register_pci'
drivers/usb/host/xhci-pci.c:182:26: warning: non-ANSI function declaration of function 'xhci_unregister_pci'
drivers/usb/host/xhci-ring.c:342:32: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:525:34: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1009:32: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1031:32: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1041:16: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1096:30: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-ring.c:1100:27: warning: Using plain integer as NULL pointer
drivers/usb/host/xhci-mem.c:224:27: warning: symbol 'xhci_alloc_container_ctx' was not declared. Should it be static?
drivers/usb/host/xhci-mem.c:242:6: warning: symbol 'xhci_free_container_ctx' was not declared. Should it be static?
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Lothar Wassmann <LW@KARO-electronics.de>
Signed-off By: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Much of the xHCI driver code assumes that endpoints only have one ring.
Now an endpoint can have one ring per enabled stream ID, so correct that
assumption. Use functions that translate the stream_id field in the URB
or the DMA address of a TRB into the correct stream ring.
Correct the polling loop to print out all enabled stream rings. Make the
URB cancellation routine find the correct stream ring if the URB has
stream_id set. Make sure the URB enqueueing routine does the same. Also
correct the code that handles stalled/halted endpoints.
Check that commands and registers that can take stream IDs handle them
properly. That includes ringing an endpoint doorbell, resetting a
stalled/halted endpoint, and setting a transfer ring dequeue pointer
(since that command can set the dequeue pointer in a stream context or an
endpoint context).
Correct the transfer event handler to translate a TRB DMA address into the
stream ring it was enqueued to. Make the code to allocate and prepare TD
structures adds the TD to the right td_list for the stream ring. Make
sure the code to give the first TRB in a TD to the hardware manipulates
the correct stream ring.
When an endpoint stalls, store the stream ID of the stream ring that
stalled in the xhci_virt_ep structure. Use that instead of the stream ID
in the URB, since an URB may be re-used after it is given back after a
non-control endpoint stall.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add support for allocating streams for USB 3.0 bulk endpoints. See
Documentation/usb/bulk-streams.txt for more information about how and why
you would use streams.
When an endpoint has streams enabled, instead of having one ring where all
transfers are enqueued to the hardware, it has several rings. The ring
dequeue pointer in the endpoint context is changed to point to a "Stream
Context Array". This is basically an array of pointers to transfer rings,
one for each stream ID that the driver wants to use.
The Stream Context Array size must be a power of two, and host controllers
can place a limit on the size of the array (4 to 2^16 entries). These
two facts make calculating the size of the Stream Context Array and the
number of entries actually used by the driver a bit tricky.
Besides the Stream Context Array and rings for all the stream IDs, we need
one more data structure. The xHCI hardware will not tell us which stream
ID a transfer event was for, but it will give us the slot ID, endpoint
index, and physical address for the TRB that caused the event. For every
endpoint on a device, add a radix tree to map physical TRB addresses to
virtual segments within a stream ring.
Keep track of whether an endpoint is transitioning to using streams, and
don't enqueue any URBs while that's taking place. Refuse to transition an
endpoint to streams if there are already URBs enqueued for that endpoint.
We need to make sure that freeing streams does not fail, since a driver's
disconnect() function may attempt to do this, and it cannot fail.
Pre-allocate the command structure used to issue the Configure Endpoint
command, and reserve space on the command ring for each stream endpoint.
This may be a bit overkill, but it is permissible for the driver to
allocate all streams in one call and free them in multiple calls. (It is
not advised, however, since it is a waste of resources and time.)
Even with the memory and ring room pre-allocated, freeing streams can
still fail because the xHC rejects the configure endpoint command. It is
valid (by the xHCI 0.96 spec) to return a "Bandwidth Error" or a "Resource
Error" for a configure endpoint command. We should never see a Bandwidth
Error, since bulk endpoints do not effect the reserved bandwidth. The
host controller can still return a Resource Error, but it's improbable
since the xHC would be going from a more resource-intensive configuration
(streams) to a less resource-intensive configuration (no streams).
If the xHC returns a Resource Error, the endpoint will be stuck with
streams and will be unusable for drivers. It's an unavoidable consequence
of broken host controller hardware.
Includes bug fixes from the original patch, contributed by
John Youn <John.Youn@synopsys.com> and Andy Green <AGreen@PLXTech.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1368) fixes a rather obscure bug in usbmon: When tracing
URBs sent by the scatter-gather library, it accesses the data buffers
while they are still mapped for DMA.
The solution is to move the mapping and unmapping out of the s-g
library and into the usual place in hcd.c. This requires the addition
of new URB flag bits to describe the kind of mapping needed, since we
have to call dma_map_sg() if the HCD supports native scatter-gather
operation and dma_map_page() if it doesn't. The nice thing about
having the new flags is that they simplify the testing for unmapping.
The patch removes the only caller of usb_buffer_[un]map_sg(), so those
functions are #if'ed out. A later patch will remove them entirely.
As a result of this change, urb->sg will be set in situations where
it wasn't set previously. Hence the xhci and whci drivers are
adjusted to test urb->num_sgs instead, which retains its original
meaning and is nonzero only when the HCD has to handle a scatterlist.
Finally, even when a submission error occurs we don't want to hand
URBs to usbmon before they are unmapped. The submission path is
rearranged so that map_urb_for_dma() is called only for non-root-hub
URBs and unmap_urb_for_dma() is called immediately after a submission
error. This simplifies the error handling.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The length of the scatter gather list a driver can enqueue is limited by
the bus' sg_tablesize to 62 entries. Each entry will be described by at
least one transfer request block (TRB). If the entry's buffer crosses a
64KB boundary, then that entry will have to be described by two or more
TRBs. So even if the USB device driver respects sg_tablesize, the whole
scatter list may take more than 62 TRBs to describe, and won't fit on
the ring.
Don't assume that an empty ring means there is enough room on the
transfer ring. The old code would unconditionally queue this too-large
transfer, and over write the beginning of the transfer. This would mean
the cycle bit was unchanged in those overwritten transfers, causing the
hardware to think it didn't own the TRBs, and the host would seem to
hang.
Now drivers may see submit_urb() fail with -ENOMEM if the transfers are
too big to fit on the ring.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When the USB core installs a new interface, it unconditionally clears the
halts on all the endpoints on the new interface. Usually the xHCI host
needs to know when an endpoint is reset, so it can change its internal
endpoint state. In this case, it doesn't care, because the endpoints were
never halted in the first place.
To avoid issuing a redundant Reset Endpoint command, the xHCI driver looks
at xhci_virt_ep->stopped_td to determine if the endpoint was actually
halted. However, the functions that handle the stall never set that
variable to NULL after it dealt with the stall. So if an endpoint stalled
and a Reset Endpoint command completed, and then the class driver tried to
install a new alternate setting, the xHCI driver would access the old
xhci_virt_ep->stopped_td pointer. A similar problem occurs if the
endpoint has been stopped to cancel a transfer.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
When a USB device is reset, the xHCI hardware must know, in order to match
the device state and disable all endpoints except control endpoint 0.
Issue a Reset Device command after a USB device is successfully reset.
Wait on the command to finish, and then cache or free the disabled
endpoint rings.
There are four different USB device states that the xHCI hardware tracks:
- disabled/enabled - device connection has just been detected,
- default - the device has been reset and has an address of 0,
- addressed - the device has a non-zero address but no configuration has
been set,
- configured - a set configuration succeeded.
The USB core may issue a port reset when a device is in any state, but the
Reset Device command will fail for a 0.96 xHC if the device is not in the
addressed or configured state. Don't consider this failure as an error,
but don't free any endpoint rings if this command fails.
A storage driver may request that the USB device be reset during error
handling, so use GPF_NOIO instead of GPF_KERNEL while allocating memory
for the Reset Device command.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
All commands that can be issued to the xHCI hardware can come back with
vendor-specific "informational" completion codes. These are to be treated
like a successful completion code. Refactor out the code to test for the
range of these codes and print debugging messages.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The xHCI driver issues a Configure Endpoint command for two reasons:
- a new configuration or alternate interface setting is selected
- a quirky Fresco Logic prototype requires the command after a Reset
Endpoint command.
The xHCI driver only waits on the command in the first case.
When a configure endpoint command completes, the driver needs to know why
the command was generated. When the driver only supported selecting an
initial configuration, the check was simple. Unfortunately that check
doesn't work now that the driver supports alternate interfaces. If an
endpoint must be dropped (because it's not in the new alternate setting)
and no new endpoints are added, the math involving
xhci_last_valid_endpoint() will assign -1 to an unsigned integer and cause
an out-of-bounds array access.
Move the check for the quirky hardware sooner and avoid the bad array
access.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The xHCI 0.95 and 0.96 specification defines several transfer buffer
request completion codes that indicate a USB transaction error occurred.
When a stall, babble, transaction, or split transaction error completion code
is set, the xHCI has halted that endpoint ring. Software must issue a
Reset Endpoint command and a Set Transfer Ring Dequeue Pointer command
to clean up the halted ring.
The USB device driver is supposed to call into usb_reset_endpoint() when
an endpoint stalls. That calls into the xHCI driver to issue the proper
commands. However, drivers don't call that function for the other
errors that cause the xHC to halt the endpoint ring. If a babble,
transaction, or split transaction error occurs, check if the endpoint
context reports a halted condition, and clean up the endpoint ring if it
does.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
An xHCI host controller manufacturer can choose to implement several
vendor-specific informational completion codes. These are all to be
treated like a successful transfer completion.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When the xHCI hardware says a transfer completed with a split
transaction error, set the URB status to -EPROTO.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The transfer descriptor (TD) is a series of transfer request buffers
(TRBs) that describe the buffer pointer, length, and other
characteristics. The xHCI controllers want to know an estimate of how
long the TD is, for caching reasons. In each TRB, there is a "TD size"
field that provides a rough estimate of the remaining buffers to be
transmitted, including the buffer pointed to by that TRB.
The TD size is 5 bits long, and contains the remaining size in bytes,
right shifted by 10 bits. So a remaining TD size less than 1024 would get
a zero in the TD size field, and a remaining size greater than 32767 would
get 31 in the field.
This patches fixes a bug in the TD_REMAINDER macro that is triggered when
the URB has a scatter gather list with a size bigger than 32767 bytes.
Not all host controllers pay attention to the TD size field, so the bug
will not appear on all USB 3.0 hosts.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It's not surprising that the transfer request buffer (TRB) physical to
virtual address translation function has bugs in it, since I wrote most of
it at 4am last October. Add a test suite to check the TRB math. This
runs at memory initialization time, and causes the driver to fail to load
if the TRB math fails.
Please excuse the excessively long lines in the test vectors; they can't
really be made shorter and still be readable.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
CONFIG_USB_HCD_STAT was used in an abandoned patch to track host
controller throughput statistics. Since CONFIG_USB_HCD_STAT will never be
defined, remove code that can never run.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In order to giveback a canceled URB, we must ensure that the xHCI
hardware will not access the buffer in an URB. We can't modify the
buffer pointers on endpoint rings without issuing and waiting for a stop
endpoint command. Since URBs can be canceled in interrupt context, we
can't wait on that command. The old code trusted that the host
controller would respond to the command, and would giveback the URBs in
the event handler. If the hardware never responds to the stop endpoint
command, the URBs will never be completed, and we might hang the USB
subsystem.
Implement a watchdog timer that is spawned whenever a stop endpoint
command is queued. If a stop endpoint command event is found on the
event ring during an interrupt, we need to stop the watchdog timer with
del_timer(). Since del_timer() can fail if the timer is running and
waiting on the xHCI lock, we need a way to signal to the timer that
everything is fine and it should exit. If we simply clear
EP_HALT_PENDING, a new stop endpoint command could sneak in and set it
before the watchdog timer can grab the lock.
Instead we use a combination of the EP_HALT_PENDING flag and a counter
for the number of pending stop endpoint commands
(xhci_virt_ep->stop_cmds_pending). If we need to cancel the watchdog
timer and del_timer() succeeds, we decrement the number of pending stop
endpoint commands. If del_timer() fails, we leave the number of pending
stop endpoint commands alone. In either case, we clear the
EP_HALT_PENDING flag.
The timer will decrement the number of pending stop endpoint commands
once it obtains the lock. If the timer is the tail end of the last stop
endpoint command (xhci_virt_ep->stop_cmds_pending == 0), and the
endpoint's command is still pending (EP_HALT_PENDING is set), we assume
the host is dying. The watchdog timer will set XHCI_STATE_DYING, try to
halt the xHCI host, and give back all pending URBs.
Various other places in the driver need to check whether the xHCI host
is dying. If the interrupt handler ever notices, it should immediately
stop processing events. The URB enqueue function should also return
-ESHUTDOWN. The URB dequeue function should simply return the value
of usb_hcd_check_unlink_urb() and the watchdog timer will take care of
giving the URB back. When a device is disconnected, the xHCI hardware
structures should be freed without issuing a disable slot command (since
the hardware probably won't respond to it anyway). The debugging
polling loop should stop polling if the host is dying.
When a device is disconnected, any pending watchdog timers are killed
with del_timer_sync(). It must be synchronous so that the watchdog
timer doesn't attempt to access the freed endpoint structures.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In the old code, there was a race condition between the stop endpoint
command and the URB submission process. When the stop endpoint command is
handled by the event handler, the endpoint ring is assumed to be stopped.
When a stop endpoint command is queued, URB submissions are to not ring
the doorbell. The old code would check the number of pending URBs to be
canceled, and would not ring the doorbell if it was non-zero.
However, the following race condition could occur with the old code:
1. Cancel an URB, add it to the list of URBs to be canceled, queue the stop
endpoint command, and increment ep->cancels_pending to 1.
2. The URB finishes on the HW, and an event is enqueued to the event ring
(at the same time as 1).
3. The stop endpoint command finishes, and the endpoint is halted. An
event is queued to the event ring.
4. The event handler sees the finished URB, notices it was to be
canceled, decrements ep->cancels_pending to 0, and removes it from the to
be canceled list.
5. The event handler drops the lock and gives back the URB. The
completion handler requeues the URB (or a different driver enqueues a new
URB). This causes the endpoint's doorbell to be rung, since
ep->cancels_pending == 0. The endpoint is now running.
6. A second URB is canceled, and it's added to the canceled list.
Since ep->cancels_pending == 0, a new stop endpoint command is queued, and
ep->cancels_pending is incremented to 1.
7. The event handler then sees the completed stop endpoint command. The
handler assumes the endpoint is stopped, but it isn't. It attempts to
move the dequeue pointer or change TDs to cancel the second URB, while the
hardware is actively accessing the endpoint ring.
To eliminate this race condition, a new endpoint state bit is introduced,
EP_HALT_PENDING. When this bit is set, a stop endpoint command has been
queued, and the command handler has not begun to process the URB
cancellation list yet. The endpoint doorbell should not be rung when this
is set. Set this when a stop endpoint command is queued, clear it when
the handler for that command runs, and check if it's set before ringing a
doorbell. ep->cancels_pending is eliminated, because it is no longer
used.
Make sure to ring the doorbell for an endpoint when the stop endpoint
command handler runs, even if the canceled URB list is empty. All
canceled URBs could have completed and new URBs could have been enqueued
without the doorbell being rung before the command was handled.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The trb_in_td() function in the xHCI driver is supposed to translate a
physical transfer buffer request (TRB) into a virtual pointer to the ring
segment that TRB is in.
Unfortunately, a mistake in this function may cause endless loops as the
driver searches through the linked list of ring segments over and over
again. Fix a couple bugs that may lead to loops or bad output:
1. Bail out if we get a NULL pointer when translating the segment's
private structure and the starting DMA address of the segment chunk. If
this happens, we've been handed a starting TRB pointer from a different
ring.
2. Make sure the function works when there's multiple segments in the
ring. In the while loop to search through the ring segments, use the
current segment variable (cur_seg), rather than the starting segment
variable (start_seg) that is passed in.
3. Stop searching the ring if we've run through all the segments in the
ring.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
For a USB hub to work under an xHCI host controller, the xHC's internal
scheduler must be made aware of the hub's characteristics. Add an xHCI
hook that the USB core will call after it fetches the hub descriptor.
This hook will add hub information to the slot context for that device,
including whether it has multiple TTs or a single TT, the number of ports
on the hub, and TT think time.
Setting up the slot context for the device is different for 0.95 and 0.96
xHCI host controllers.
Some of the slot context reserved fields in the 0.95 specification were
changed into hub fields in the 0.96 specification. Don't set the TT think
time or number of ports for a hub if we're dealing with a 0.95-compliant
xHCI host controller.
The 0.95 xHCI specification says that to modify the hub flag, we need to
issue an evaluate context command. The 0.96 specification says that flag
can be set with a configure endpoint command. Issue the correct command
based on the version reported by the hardware.
This patch does not add support for multi-TT hubs. Multi-TT hubs expose
a single TT on alt setting 0, and multi-TT on alt setting 1. The xHCI
driver can't handle setting alternate interfaces yet.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In the xHCI driver, configure endpoint commands that are submitted to the
hardware may involve one of two data structures. If the configure
endpoint command is setting up a new configuration or modifying max packet
sizes, the data structures and completions are statically allocated in the
xhci_virt_device structure. If the command is being used to set up
streams or add hub information, then the data structures are dynamically
allocated, and placed on a device command waiting list.
Break out the code to check whether a completed command is in the device
command waiting list. Fix a subtle bug in the old code: continue
processing the command if the command isn't in the wait list. In the old
code, if there was a command in the wait list, but it didn't match the
completed command, the completed command event would be dropped.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some commands to the xHCI hardware cannot be allowed to fail due to out of
memory issues or the command ring being full.
Add a way to reserve a TRB on the command ring, and make all command
queueing functions indicate whether they are using a reserved TRB.
Add a way to pre-allocate all the memory a command might need. A command
needs an input context, a variable to store the status, and (optionally) a
completion for the caller to wait on. Change all code that assumes the
input device context, status, and completion for a command is stored in
the xhci virtual USB device structure (xhci_virt_device).
Store pending completions in a FIFO in xhci_virt_device. Make the event
handler for a configure endpoint command check to see whether a pending
command in the list has completed. We need to use separate input device
contexts for some configure endpoint commands, since multiple drivers can
submit requests at the same time that require a configure endpoint
command.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The xhci_ring structure contained information that is really related to an
endpoint, not a ring. This will cause problems later when endpoint
streams are supported and there are multiple rings per endpoint.
Move the endpoint state and cancellation information into a new virtual
endpoint structure, xhci_virt_ep. The list of TRBs to be cancelled should
be per endpoint, not per ring, for easy access. There can be only one TRB
that the endpoint stopped on after a stop endpoint command (even with
streams enabled); move the stopped TRB information into the new virtual
endpoint structure. Also move the 31 endpoint rings and temporary ring
storage from the virtual device structure (xhci_virt_device) into the
virtual endpoint structure (xhci_virt_ep).
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Interrupt transfers are submitted to the xHCI hardware using the same TRB
type as bulk transfers. Re-use the bulk transfer enqueueing code to
enqueue interrupt transfers.
Interrupt transfers are a bit different than bulk transfers. When the
interrupt endpoint is to be serviced, the xHC will consume (at most) one
TD. A TD (comprised of sg list entries) can take several service
intervals to transmit. The important thing for device drivers to note is
that if they use the scatter gather interface to submit interrupt
requests, they will not get data sent from two different scatter gather
lists in the same service interval.
For now, the xHCI driver will use the service interval from the endpoint's
descriptor (bInterval). Drivers will need a hook to poll at a more
frequent interval. Set urb->interval to the interval that the xHCI
hardware will use.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The xHCI hardware reports the number of bytes untransferred for a given
transfer buffer. If the hardware reports a bytes untransferred value
greater than the submitted buffer size, we want to play it safe and say no
data was transferred. If the driver considers a short packet to be an
error, remember to set -EREMOTEIO.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make sure that the driver that submitted the URB considers a short packet
an error before setting -EREMOTEIO during a short control transfer.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make sure that the amount of data the xHC says was transmitted is less
than or equal to the size of the requested transfer buffer. Before, if
the host controller erroneously reported that the number of bytes
untransferred was bigger than the buffer in the URB, urb->actual_length
could be set to a very large size.
Make sure urb->actual_length <= urb->transfer_buffer_length.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On a successful transfer, urb->td is freed before the URB is ready to be
given back to the driver. Don't touch urb->td after it's freed. This bug
would have only shown up when xHCI debugging was turned on, and the freed
memory was quickly reused for something else.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The 0.95 xHCI spec says that non-control endpoints will be halted if a
babble is detected on a transfer. The 0.96 xHCI spec says all types of
endpoints will be halted when a babble is detected. Some hardware that
claims to be 0.95 compliant halts the control endpoint anyway.
When a babble is detected on a control endpoint, check the hardware's
output endpoint context to see if the endpoint is marked as halted. If
the control endpoint is halted, a reset endpoint command must be issued
and the transfer ring dequeue pointer needs to be moved past the stopped
transfer. Basically, we treat it as if the control endpoint had stalled.
Handle bulk babbling endpoints as if we got a completion event with a
stall completion code.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use trb_comp_code instead of getting the completion code from the transfer
event every time.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This Fresco Logic xHCI host controller chip revision puts bad data into
the output endpoint context after a Reset Endpoint command. It needs a
Configure Endpoint command (instead of a Set TR Dequeue Pointer command)
after the reset endpoint command.
Set up the input context before issuing the Reset Endpoint command so we
don't copy bad data from the output endpoint context. The HW also can't
handle two commands queued at once, so submit the TRB for the Configure
Endpoint command in the event handler for the Reset Endpoint command.
Devices that stall on control endpoints before a configuration is selected
will not work under this Fresco Logic xHCI host controller revision.
This patch is for prototype hardware that will be given to other companies
for evaluation purposes only, and should not reach consumer hands. Fresco
Logic's next chip rev should have this bug fixed.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When a control endpoint stalls, the next control transfer will clear the
stall. The USB core doesn't call down to the host controller driver's
endpoint_reset() method when control endpoints stall, so the xHCI driver
has to do all its stall handling for internal state in its interrupt handler.
When the host stalls on a control endpoint, it may stop on the data phase
or status phase of the control transfer. Like other stalled endpoints,
the xHCI driver needs to queue a Reset Endpoint command and move the
hardware's control endpoint ring dequeue pointer past the failed control
transfer (with a Set TR Dequeue Pointer or a Configure Endpoint command).
Since the USB core doesn't call usb_hcd_reset_endpoint() for control
endpoints, we need to do this in interrupt context when we get notified of
the stalled transfer. URBs may be queued to the hardware before these two
commands complete. The endpoint queue will be restarted once both
commands complete.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Full speed devices have varying max packet sizes (8, 16, 32, or 64) for
endpoint 0. The xHCI hardware needs to know the real max packet size
that the USB core discovers after it fetches the first 8 bytes of the
device descriptor.
In order to fix this without adding a new hook to host controller drivers,
the xHCI driver looks for an updated max packet size for control
endpoints. If it finds an updated size, it issues an evaluate context
command and waits for that command to finish. This should only happen in
the initialization and device descriptor fetching steps in the khubd
thread, so blocking should be fine.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Refactor out the code issue, wait for, and parse the event completion code
for a configure endpoint command. Modify it to support the evaluate
context command, which has a very similar submission process. Add
functions to copy parts of the output context into the input context
(which will be used in the evaluate context command).
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Different sections of the xHCI 0.95 specification had opposing
requirements for the chain bit in a link transaction request buffer (TRB).
The chain bit is used to designate that adjacent TRBs are all part of the
same scatter gather list that should be sent to the device. Link TRBs can
be in the middle, or at the beginning or end of these chained TRBs.
Sections 4.11.5.1 and 6.4.4.1 both stated the link TRB "shall have the
chain bit set to 1", meaning it is always chained to the next TRB.
However, section 4.6.9 on the stop endpoint command has specific cases for
what the hardware must do for a link TRB with the chain bit set to 0. The
0.96 specification errata later cleared up this issue by fixing the
4.11.5.1 and 6.4.4.1 sections to state that a link TRB can have the chain
bit set to 1 or 0.
The problem is that the xHCI cancellation code depends on the chain bit of
the link TRB being cleared when it's at the end of a TD, and some 0.95
xHCI hardware simply stops processing the ring when it encounters a link
TRB with the chain bit cleared.
Allow users who are testing 0.95 xHCI prototypes to set a module parameter
(link_quirk) to turn on this link TRB work around. Cancellation may not
work if the ring is stopped exactly on a link TRB with chain bit set, but
cancellation should be a relatively uncommon case.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Correct the xHCI code to handle stalls on USB endpoints. We need to move
the endpoint ring's dequeue pointer past the stalled transfer, or the HW
will try to restart the transfer the next time the doorbell is rung.
Don't attempt to clear a halt on an endpoint if we haven't seen a stalled
transfer for it. The USB core will attempt to clear a halt on all
endpoints when it selects a new configuration.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Adds support for controllers that use 64-byte contexts. The following context
data structures are affected by this: Device, Input, Input Control, Endpoint,
and Slot. To accommodate the use of either 32 or 64-byte contexts, a Device or
Input context can only be accessed through functions which look-up and return
pointers to their contained contexts.
Signed-off-by: John Youn <johnyoun@synopsys.com>
Acked-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Pass back a babble error when this error code is seen in the transfer event TRB.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add more debugging to the irq handler, slot context initialization, ring
operations, URB cancellation, and MMIO writes.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The Event Handler Busy bit in the event ring dequeue pointer is write 1 to
clear. Fix the interrupt service routine to clear that bit after the
event handler has run.
xhci_set_hc_event_deq() is designed to update the event ring dequeue pointer
without changing any of the four reserved bits in the lower nibble. The event
handler busy (EHB) bit is write one to clear, so the new value must always
contain a zero in that bit in order to preserve the EHB value.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When there is a short packet on a control transfer, the xHCI host controller
hardware will generate two events. The first event will be for the data stage
TD with a completion code for a short packet. The second event will be for the
status stage with a successful completion code. Before this patch, the xHCI
driver would giveback the short control URB when it received the event for the
data stage TD. Then it would become confused when it saw a status stage event
for the endpoint for an URB it had already finished processing.
Change the xHCI host controller driver to wait for the status stage event when
it receives a short transfer completion code for a data stage TD.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
