linux/drivers/usb
Matthew Wilcox b214f191d9 USB: Fix unplug of device with active streams
If I unplug a device while the UAS driver is loaded, I get an oops
in usb_free_streams().  This is because usb_unbind_interface() calls
usb_disable_interface() which calls usb_disable_endpoint() which sets
ep_out and ep_in to NULL.  Then the UAS driver calls usb_pipe_endpoint()
which returns a NULL pointer and passes an array of NULL pointers to
usb_free_streams().

I think the correct fix for this is to check for the NULL pointer
in usb_free_streams() rather than making the driver check for this
situation.  My original patch for this checked for dev->state ==
USB_STATE_NOTATTACHED, but the call to usb_disable_interface() is
conditional, so not all drivers would want this check.

Note from Sarah Sharp: This patch does avoid a potential dereference,
but the real fix (which will be implemented later) is to set the
.soft_unbind flag in the usb_driver structure for the UAS driver, and
all drivers that allocate streams.  The driver should free any streams
when it is unbound from the interface.  This avoids leaking stream rings
in the xHCI driver when usb_disable_interface() is called.

This should be queued for stable trees back to 2.6.35.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
2011-04-13 16:57:33 -07:00
..
atm Fix common misspellings 2011-03-31 11:26:23 -03:00
c67x00 Fix common misspellings 2011-03-31 11:26:23 -03:00
class Fix common misspellings 2011-03-31 11:26:23 -03:00
core USB: Fix unplug of device with active streams 2011-04-13 16:57:33 -07:00
early Fix common misspellings 2011-03-31 11:26:23 -03:00
gadget USB: fsl_qe_udc: send ZLP when zero flag and length % maxpacket == 0 2011-04-13 15:57:19 -07:00
host USB: xhci - also free streams when resetting devices 2011-04-13 16:57:31 -07:00
image Fix common misspellings 2011-03-31 11:26:23 -03:00
misc Fix common misspellings 2011-03-31 11:26:23 -03:00
mon USB: usbmon: fix-up docs and text API for sparse ISO 2011-02-04 11:46:57 -08:00
musb usb: musb: omap2430: fix build failure 2011-04-13 15:44:02 -07:00
otg Fix common misspellings 2011-03-31 11:26:23 -03:00
serial usb: qcserial add missing errorpath kfrees 2011-04-13 15:53:16 -07:00
storage Fix common misspellings 2011-03-31 11:26:23 -03:00
wusbcore Fix common misspellings 2011-03-31 11:26:23 -03:00
Kconfig usb: Fix Kconfig unmet dependencies for Microblaze EHCI 2011-04-13 15:43:59 -07:00
Makefile USB: drivers/usb/Makefile: conditionally descend to 'early' 2010-08-10 14:35:38 -07:00
README
usb-skeleton.c llseek: automatically add .llseek fop 2010-10-15 15:53:27 +02:00

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.