linux/drivers/usb
Sarah Sharp 44ebd037c5 USB: xhci: Fix check for room on the ring.
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>
2010-05-20 13:21:30 -07:00
..
atm include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
c67x00 include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
class USB: cdc-acm: add another device quirk 2010-04-30 09:25:10 -07:00
core Fix the regression created by "set S_DEAD on unlink()..." commit 2010-05-15 07:16:33 -04:00
early USB: ehci-dbgp: split PID register updates for IN and OUT pipes 2010-03-02 14:54:58 -08:00
gadget USB: gadget: s3c-hsotg: Add missing unlock 2010-04-30 09:25:11 -07:00
host USB: xhci: Fix check for room on the ring. 2010-05-20 13:21:30 -07:00
image USB: BKL removal: mdc800 2010-03-02 14:54:27 -08:00
misc USB: fixed bug in usbsevseg using USB autosuspend incorrectly 2010-04-22 15:18:21 -07:00
mon include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
musb usb: Fix tusb6010 for DMA API 2010-04-30 09:25:09 -07:00
otg include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
serial USB: ti_usb: fix printk format warning 2010-04-30 09:25:11 -07:00
storage include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
wusbcore usb: wusb: don't overflow the Keep Alive IE buffer 2010-04-22 15:18:22 -07:00
Kconfig Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6 2010-03-03 08:48:58 -08:00
Makefile USB: MXC: Add i.MX21 specific USB host controller driver. 2010-03-02 14:52:55 -08:00
README
usb-skeleton.c USB: BKL removal: usb-skeleton 2010-03-02 14:54:26 -08:00

To understand all the Linux-USB framework, you'll use these resources:

    * This source code.  This is necessarily an evolving work, and
      includes kerneldoc that should help you get a current overview.
      ("make pdfdocs", and then look at "usb.pdf" for host side and
      "gadget.pdf" for peripheral side.)  Also, Documentation/usb has
      more information.

    * The USB 2.0 specification (from www.usb.org), with supplements
      such as those for USB OTG and the various device classes.
      The USB specification has a good overview chapter, and USB
      peripherals conform to the widely known "Chapter 9".

    * Chip specifications for USB controllers.  Examples include
      host controllers (on PCs, servers, and more); peripheral
      controllers (in devices with Linux firmware, like printers or
      cell phones); and hard-wired peripherals like Ethernet adapters.

    * Specifications for other protocols implemented by USB peripheral
      functions.  Some are vendor-specific; others are vendor-neutral
      but just standardized outside of the www.usb.org team.

Here is a list of what each subdirectory here is, and what is contained in
them.

core/		- This is for the core USB host code, including the
		  usbfs files and the hub class driver ("khubd").

host/		- This is for USB host controller drivers.  This
		  includes UHCI, OHCI, EHCI, and others that might
		  be used with more specialized "embedded" systems.

gadget/		- This is for USB peripheral controller drivers and
		  the various gadget drivers which talk to them.


Individual USB driver directories.  A new driver should be added to the
first subdirectory in the list below that it fits into.

image/		- This is for still image drivers, like scanners or
		  digital cameras.
../input/	- This is for any driver that uses the input subsystem,
		  like keyboard, mice, touchscreens, tablets, etc.
../media/	- This is for multimedia drivers, like video cameras,
		  radios, and any other drivers that talk to the v4l
		  subsystem.
../net/		- This is for network drivers.
serial/		- This is for USB to serial drivers.
storage/	- This is for USB mass-storage drivers.
class/		- This is for all USB device drivers that do not fit
		  into any of the above categories, and work for a range
		  of USB Class specified devices. 
misc/		- This is for all USB device drivers that do not fit
		  into any of the above categories.