Changed definition of usb_composite_unregister() function
removing __exit declaration. This way, the function is
included even if the whole code was not compiled as module.
This is required if a compiled-in code would like to
unregister a composite gadget.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Most of the data from fsg_dev have been moved to fsg_common
structure. The fsg_dev structure holds only endpoint dependent
data. The fsg_common structure has a fsg pointer which points
to active fsg_dev structure -- endpoints are referenced via this
pointer.
This fixes the problem of several threads created when a single
instance of MSF is used in several USB configurations.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fixed most of the errors and warnings in f_mass_storage.c and
storage_common.c reported by checkpatch.pl as well as updated
comments.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
A two fsg_config fields were added:
* lun_name_format which lets one specify format of a name
used when registering LUN devices. It is useful if there
would be ever need for two MSFs to be used in a single
composite gadget (as opposed to single MSF in two
configuration); and
* thread_name which lets one specify the name of a kernel
thread used by MSF. This is not required since two or more
threads can have the same name but nevertheless it's here
for consistency.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Removed all references to mod_data in f_mass_storage.c and
instead created fsg_config structure fsg_common_init() takes
as an argument -- it stores all configuration options that
were previously taken from mod_data.
Moreover, The fsg_config structure allows per-LUN
configuration of removable and CD-ROM emulation.
Module parameters are handled by defining an object of
fsg_module_parameters structure and then declaring module
parameters via FSG_MODULE_PARAMETERS() macro. It adds proper
declarations to the code making specified object be populated
from module parameters.
To use values stored there one may use either
fsg_config_from_params() which will will a fsg_config structure
with values taken from fsg_module_parameters structure or
fsg_common_from_params() which will initialise fsg_common
structure directly.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The f_mass_storage.c has been changed into a composite function.
mass_storage.c file has been introduced which defines a
g_mass_storage gadget based on composite framework.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.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>
Allow module_param to be writeable. This allows us to change
the parameter if usbtest is built-in in the kernel.
Signed-off-by: Vikram Pandita <vikram.pandita@ti.com>
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add a missing goto. We dereference usb_class on the next line.
Found by smatch static checker.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
td and dev can not be null.
Also they are dereferenced in list_for_each_entry_safe and list_for_each
before the check happens so we would have an oops if it were possible
for them to be null.
Found using the smatch static checker.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1302) removes the auto_pm flag from struct usb_device.
The flag's only purpose was to distinguish between autosuspends and
external suspends, but that information is now available in the
pm_message_t argument passed to suspend methods.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Quiet the following sparse noise:
warning: Using plain integer as NULL pointer
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add D-Link DWM-162-U5 device id 1e0e:ce16 into option driver. The device
has 4 interfaces, of which 1 is handled by storage and the other 3 by
option driver.
The device appears first as CD-only 05c6:2100 device and must be switched
to 1e0e:ce16 mode either by using "eject CD" or usb_modeswitch.
The MessageContent for usb_modeswitch.conf is:
"55534243e0c26a85000000000000061b000000020000000000000000000000"
Signed-off-by: Zhang Le <r0bertz@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
USB drivers that create character devices call usb_register_dev in their
probe function. This associates the usb_interface device with that minor
number and creates the character device and announces it to the world.
However, the driver's probe function is called before the new
usb_interface is added to the driver's klist_devices.
This is a problem because userspace will respond to the character device
creation announcement by opening the character device. The driver's open
function will the call usb_find_interface to find the usb_interface
associated with that minor number. usb_find_interface will walk the
driver's list of devices and find the usb_interface with the matching
minor number.
Because the announcement happens before the usb_interface is added to the
driver's klist_devices, a race condition exists. A straightforward fix
is to walk the list of devices on usb_bus_type instead since the device
is added to that list before the announcement occurs.
bus_find_device calls get_device to bump the reference count on the found
device. It is arguable that the reference count should be dropped by the
caller of usb_find_interface instead of usb_find_interface, however,
the current users of usb_find_interface do not expect this.
Signed-off-by: Russ Dill <Russ.Dill@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
istl_flip is a signed bitfield of one bit so it can be -1 or 0.
However in drivers/usb/host/isp1362-hcd.c:1103:
finish_iso_transfers(isp1362_hcd,
&isp1362_hcd->istl_queue[isp1362_hcd->istl_flip]);
So if isp1362_hcd->istl_flip is set, the 2nd argument becomes
&isp1362_hcd->istl_queue[-1], which is invalid.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes a bug when incrementing/decrementing on a BCD formatted
integer (i.e. 0x09++ should be 0x10 not 0x0A). It just adds a function
for incrementing/decrementing BCD integers by converting to decimal,
doing the increment/decrement and then converting back to BCD.
Signed-off-by: Nathaniel McCallum <nathaniel@natemccallum.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The current code to generate usb modaliases from usb_device_id assumes
that the device's bcdDevice descriptor will actually be in BCD format.
While this should be a sane assumption, some devices don't follow spec
and just use plain old hex. This causes drivers for these devices to
generate invalid modalias lines which will never actually match for the
hardware.
The following patch adds hex support for bcdDevice in file2alias.c by
detecting when a driver uses a hex formatted bcdDevice_(lo|hi) and
adjusts the output to hex format accordingly.
Drivers for devices which have bcdDevice conforming to BCD will have no
change in modalias output. Drivers for devices which don't conform
(i.e. ibmcam) should now generate valid modaliases.
EXAMPLE OUTPUT (ibmcam; space added to highlight change)
Old: usb:v0545p800D d030[10-9] dc*dsc*dp*ic*isc*ip*
New: usb:v0545p800D d030a dc*dsc*dp*ic*isc*ip*
Signed-off-by: Nathaniel McCallum <nathaniel@natemccallum.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Nokia S60 phones expose two ACM channels. The first is a modem and is picked
up by the standard AT-command interface information in the CDC-ACM driver. The
second is marked as having a vendor-specific protocol. Normally, we don't
expose those as ttys. (On some other devices, they may be claimed by the
rndis_host driver and used as a network interface).
But on S60 this second ACM channel is the way that third-party S60 application
developers are expected to communicate over USB. It acts as a serial device
at the S60 end, and so it should on Linux too.
The list of devices is largely derived from:
http://wiki.forum.nokia.com/index.php/S60_Platform_and_device_identification_codeshttp://wiki.forum.nokia.com/index.php/Nokia_USB_Product_IDs
and includes only the S60 3rd Edition+ devices documented there.
There are many devices for which the USB device ID is not documented,
including:
Nokia 6290
Nokia E63
Nokia 5630 XpressMusic
Nokia 5730 XpressMusic
Nokia 6710 Navigator
Nokia 6720 classic
Nokia 6730 Classic
Nokia 6760 slide
Nokia 6790 slide
Nokia 6790 Surge
Nokia E52
Nokia E55
Nokia E71x (AT&T)
Nokia E72
Nokia E75
Nokia E75 US+LTA variant
Nokia N79
Nokia N86 8MP
Nokia 5230 (RM-588)
Nokia 5230 (RM-594)
Nokia 5530 XpressMusic
Nokia 5530 XpressMusic (china)
Nokia 5800 XM
Nokia N97 (RM-506)
Nokia N97 mini
Nokia X6
It would be good to add those subsequently.
Signed-off-by: Adrian Taylor <aat@realvnc.com>
Acked-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In map_urb_for_dma(), the DMA address returned by dma_map_single()
is not checked to determine if it is legal. This lack of checking
contributed to a problem with the libertas wireless driver
(http://marc.info/?l=linux-wireless&m=125695331205062&w=2). The
difficulty was not detected until the buffer was unmapped. By this time
memory corruption had occurred.
The situation is fixed by testing the returned DMA address, and
returning -EAGAIN if the address is invalid.
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
usb: ehci: Allow EHCI to be built on OMAP3
OMAP3 chips have a built-in EHCI controller.
The recently introduced omap ehci-hcd driver missed
out on selecting USB_ARCH_HAS_EHCI in Kconfig.
Without this, the driver cannot be built.
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Cc: Vikram Pandita <vikram.pandita@ti.com>
Cc: Ajay Kumar Gupta <ajay.gupta@ti.com>
Acked-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1301) adds support to usbmon for scatter-gather URBs.
The text interface looks at only the first scatterlist element, since
it never copies more than 32 bytes of data anyway. The binary
interface copies as much data as possible up to the first
non-addressable buffer.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1300) adds native scatter-gather support to ehci-hcd.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch deals with reducing the memory footprint for sierra driver.
This optimization is aimed for embedded software customers.
Some sierra modems can expose upwards of 7 USB interfaces, each possibly
offering different services. In general, interfaces used for the
exchange of wireless data require much higher throughput, hence require
more memory (i.e. more URBs) than lower performance interfaces. URBs
used for the IN direction are pre-allocated by the driver and this patch
introduces a way to configure the number of IN URBs allocated on a
per-interface basis. Interfaces with lower throughput requirements
receive fewer URBs, thereby reducing the RAM memory consumed by the
driver.
NOTE1: This driver has always pre-allocated URBs for the IN direction.
NOTE2: The number of URBs pre-allocated for the low-performance
interfaces has already been extensively tested in previous versions of
this driver.
We also added the capability to log function calls by adding DEBUG flag.
Please note that this flag is commented out because this is the default
state
for it.
Signed-off-by: Elina Pasheva <epasheva@sierrawireless.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Without Interface Association Descriptor, the CDC serial and
RNDIS functions did not work correctly when added to a
composite gadget with other functions. This is because, it
defined two interfaces and some hosts tried to treat each
interface separatelly.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Moved code initialising fsg_common structure to fsg_common_init()
function which is called from fsg_bind(). Moreover, changed
reference counting mechanism: fsg_common has a reference counter
which counts how many fsg_dev structures uses it. When this
reaches zero fsg_common_release() is run which unregisters
LUN devices and frees memory.
fsg_common_init() takes pointer to fsg_common structure as an
argument. If it is NULL function allocates storage otherwise
uses pointed to memory (handy if fsg_common is a field of another
structure or a static variable).
fsg_common_release() will free storage only if
free_storage_on_release is set -- it is initialised by
fsg_common_init(): set if allocation was done, unset
otherwise (one may overwrite it of course).
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Using version of fsg_buffhd structure with buf field being an
array of characters with predefined size. Since mass storage
function does not define changing buffer size on run-time it is
not required for the field to be a pointer to void and allocating
space dynamically.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
In the final version, many fsg_dev structures will (be able to)
refer to a single fsg_common structure and so it is required
to move common data to another object which can be shared.
Situation where many fsg_dev structures refer single fsg_common
structure is when a single instance of MSF is used in several
USB configurations.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Removed code that was included when CONFIG_USB_FILE_STORAGE_TEST
was defined. If this functionality is required one may still use
the original File-backed Storage Gadget. It has been agreed that
testing functionality is not required in the composite function.
Also removed fsg_suspend() and fsg_resume() which were no
operations.
Moreover, storage_common.c has been modified in such a way that
defining certain macros skips parts of the file. Those macros
are:
* FSG_NO_INTR_EP -- skips interrupt endpoint descriptors
* FSG_NO_DEVICE_STRINGS -- skips certain strings
* FSG_NO_OTG -- skips OTG descriptor
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Copied file_storage.c to f_mass_storage.c which will be used as
template for the Mass Storage composite Function.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Since storage_common.c no longer references mod_data object
it is now possible to include it before mod_data object is
defined. This makes it possible to move some defines that
are used as default values of mod_data fields to be defined
in storage_common.c file (where they should be set from
the beginning).
Also, show_ro(), show_file(), store_ro() and store_file()
have been moved to storage_common.c with LUN's device's
drvdata changed from pointing to fsg_dev to pointing to
rw_semaphore (&fsg->filesem).
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
removable and cdrom flag has been added to the fsg_lun structure
removing any references to mod_data object from storage_common.c.
As of read-only flag, previously it was set if a read-only
backing file was specified (which is good) and remained set
even after the file has been closed (which may be considered an
issue). Currently, the initial read-only flag is preserved so
if it was unset each time file is opened code will try to open
it read-write even if previous file was opened read-only.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Prefixed some identifiers that were defined in storage_common.c file
with "fsg_". Not all identifiers were prefixed but the ones that are
most likely to produce conflicts when used with other USB functions.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Moved parts of the file_storage.c file which do not reference fsg_dev
structure to newly created storage_common.c file. dump_msg() and
dump_cdb() have been changed to macros to remove fsg_dev reference.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The Freescale MX27 and MX31 SoCs have a EHCI controller onboard.
The controller is capable of USB on the go. This patch adds
a driver to support all three of them.
Users have to pass details about serial interface configuration in the
platform data.
The USB OTG core used here is the ARC core, so the driver should
be renamed and probably be merged with ehci-fsl.c eventually.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1298) fixes a bug in the new scatter-gather URB
facility. If an URB uses a scatterlist then it should not have the
URB_NO_INTERRUPT flag set; otherwise the system won't be notified when
the transfer completes.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Vrabel <david.vrabel@csr.com>
CC: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1297) adds a "remove" attribute to each USB device's
directory in sysfs. Writing to this attribute causes the device to be
deconfigured (the same as writing 0 to the "bConfigurationValue"
attribute) and then tells the hub driver to disable the device's
upstream port. The device remains locked during these activities so
there is no possibility of it getting reconfigured in between. The
port will remain disabled until after the device is unplugged.
The purpose of this is to provide a means for user programs to imitate
the "Safely remove hardware" applet in Windows. Some devices do
expect their ports to be disabled before they are unplugged, and they
provide visual feedback to users indicating when they can safely be
unplugged.
The security implications are minimal. Writing to the "remove"
attribute is no more dangerous than writing to the
"bConfigurationValue" attribute.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: David Zeuthen <davidz@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1296) gets rid of the fixed DMA-buffer mapping used by
the hub driver for its status URB. This URB doesn't get used much --
mainly when a device is plugged in or unplugged -- so the dynamic
mapping overhead is minimal. And most systems have many fewer
external hubs than root hubs, which don't need a mapped buffer anyway.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The EHCI specification says that an EHCI host controller may cache part of
the isochronous schedule. The EHCI controller must advertise how much it
caches in the schedule through the HCCPARAMS register isochronous
scheduling threshold (IST) bits.
In theory, adding new iTDs within the IST should be harmless. The HW will
follow the old cached linked list and miss the new iTD. SW will notice HW
missed the iTD and return 0 for the transfer length.
However, Intel ICH9 chipsets (and some later chipsets) have issues when SW
attempts to schedule a split transaction within the IST. All transfers
will cease being sent out that port, and the drivers will see isochronous
packets complete with a length of zero. Start of frames may or may not
also disappear, causing the device to go into auto-suspend. This "bus
stall" will continue until a control or bulk transfer is queued to a
device under that roothub.
Most drivers will never cause this behavior, because they use multiple
URBs with multiple packets to keep the bus busy. If you limit the number
of URBs to one, you may be able to hit this bug.
Make sure the EHCI driver does not schedule full-speed transfers within
the IST under an Intel chipset. Make sure that when we fall behind the
current microframe plus IST, we schedule the new transfer at the next
periodic interval after the IST.
Don't change the scheduling for new transfers, since the schedule slop will
always be greater than the IST. Allow high speed isochronous transfers to
be scheduled within the IST, since this doesn't trigger the Intel chipset
bug.
Make sure that if the host caches the full frame, the EHCI driver's
internal isochronous threshold (ehci->i_thresh) is set to
8 microframes + 2 microframes wiggle room. This is similar to what is done in
the case where the host caches less than the full frame.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Change the constant SCHEDULE_SLOP to be 80 microframes, instead of 10
frames. It was always multiplied by 8 to convert frames to microframes.
SCHEDULE_SLOP is only used in ehci-sched.c.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
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>
xhci_quiesce() is basically a no-op right now. It's only called if
HC_IS_RUNNING() is true, and the body of the function consists of a
BUG_ON if HC_IS_RUNNING() is false. For the new xHCI watchdog timer, we
need a new function that clears the xHCI running bit in the command
register, but doesn't wait for the halt status to show up in the status
register. Re-purpose xhci_quiesce() to do that.
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>
usb: better error handling in usb_port_suspend
- disable remote wakeup only if it was enabled
- refuse to autosuspend if remote wakeup fails to be enabled
Signed-off-by: Oliver Neukum <oliver@neukum.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Michal Nazarewicz