linux/drivers/usb
Sarah Sharp 653a39d1f6 usb: Realloc xHCI structures after a hub is verified.
When there's an xHCI host power loss after a suspend from memory, the USB
core attempts to reset and verify the USB devices that are attached to the
system.  The xHCI driver has to reallocate those devices, since the
hardware lost all knowledge of them during the power loss.

When a hub is plugged in, and the host loses power, the xHCI hardware
structures are not updated to say the device is a hub.  This is usually
done in hub_configure() when the USB hub is detected.  That function is
skipped during a reset and verify by the USB core, since the core restores
the old configuration and alternate settings, and the hub driver has no
idea this happened.  This bug makes the xHCI host controller reject the
enumeration of low speed devices under the resumed hub.

Therefore, make the USB core re-setup the internal xHCI hub device
information by calling update_hub_device() when hub_activate() is called
for a hub reset resume.  After a host power loss, all devices under the
roothub get a reset-resume or a disconnect.

This patch should be queued for the 2.6.37 stable tree.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
2011-01-14 15:50:21 -08:00
..
atm Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2011-01-07 16:58:04 -08:00
c67x00 usb: makefile cleanup 2010-10-22 10:22:07 -07:00
class Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6 2010-10-22 20:30:48 -07:00
core usb: Realloc xHCI structures after a hub is verified. 2011-01-14 15:50:21 -08:00
early usb: makefile cleanup 2010-10-22 10:22:07 -07:00
gadget Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2011-01-07 16:58:04 -08:00
host xhci: Do not run xhci_cleanup_msix with irq disabled 2011-01-14 15:28:52 -08:00
image SCSI host lock push-down 2010-11-16 13:33:23 -08:00
misc USB: Merge 2.6.37-rc5 into usb-next 2010-12-22 12:25:34 -08:00
mon Merge branch 'usb-next' into musb-merge 2010-12-16 10:05:06 -08:00
musb headers: kobject.h redux 2011-01-10 08:51:44 -08:00
otg Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2011-01-07 16:58:04 -08:00
serial Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2011-01-07 16:58:04 -08:00
storage USB: Merge 2.6.37-rc5 into usb-next 2010-12-22 12:25:34 -08:00
wusbcore usb: makefile cleanup 2010-10-22 10:22:07 -07:00
Kconfig Merge branch 'usb-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6 2011-01-07 13:16:28 -08:00
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.