linux/drivers/usb
Daniel Mack 0cce2eda19 USB: fix LANGID=0 regression
commit b7af0bb ("USB: allow malformed LANGID descriptors") broke support
for devices without string descriptor support.

Reporting string descriptors is optional to USB devices, and a device
lets us know it can't deal with strings by responding to the LANGID
request with a STALL token.

The kernel handled that correctly before b7af0bb came in, but failed
hard if the LANGID was reported but broken. More than that, if a device
was not able to provide string descriptors, the LANGID was retrieved
over and over again at each string read request.

This patch changes the behaviour so that

 a) the LANGID is only queried once
 b) devices which can't handle string requests are not asked again
 c) devices with malformed LANGID values have a sane fallback to 0x0409

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-07-12 15:16:40 -07:00
..
atm firmware: atm/ueagle-atm: prepare for FIRMWARE_NAME_MAX removal 2009-06-15 21:30:24 -07:00
c67x00 usb/c67x00 endianness annotations 2008-06-04 08:06:01 -07:00
class USB: cdc-acm: work around some broken devices 2009-07-12 15:16:37 -07:00
core USB: fix LANGID=0 regression 2009-07-12 15:16:40 -07:00
gadget USB: gadget audio: select SND_PCM 2009-07-12 15:16:39 -07:00
host USB: EHCI: check for STALL before other errors 2009-07-12 15:16:39 -07:00
image USB: replace uses of __constant_{endian} 2009-03-24 16:20:33 -07:00
misc Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6 2009-06-16 13:06:10 -07:00
mon Fix virt_to_phys() warnings 2009-07-06 13:57:03 -07:00
musb USB: musb: silence "suspend as a_wait_vrise is_active" msgs 2009-07-12 15:16:37 -07:00
otg Revert "USB: Add Intel Langwell USB OTG Transceiver Drive" 2009-07-12 15:16:36 -07:00
serial USB: serial: sierra driver id_table additions 2009-07-12 15:16:40 -07:00
storage USB: Fix option_ms regression in 2.6.31-rc2 2009-07-12 15:16:40 -07:00
wusbcore WUSB: correct format of wusb_chid sysfs file 2009-04-17 10:50:29 -07:00
Kconfig usb: return device strings in UTF-8 2009-06-15 21:44:43 -07:00
Makefile USB: xhci: Add Makefile, MAINTAINERS, and Kconfig entries. 2009-06-15 21:44:51 -07:00
README USB: fix directory references in usb/README 2007-11-28 13:58:34 -08:00
usb-skeleton.c USB: skeleton: Use dev_info instead of info 2009-03-24 16:20:30 -07:00

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.