linux/drivers/usb
Luben Tuikov 637d11bfb8 USB: Reset USB 3.0 devices on (re)discovery
If the device isn't reset, the XHCI HCD sends
SET ADDRESS to address 0 while the device is
already in Addressed state, and the request is
dropped on the floor as it is addressed to the
default address. This sequence of events, which this
patch fixes looks like this:

usb_reset_and_verify_device()
	hub_port_init()
		hub_set_address()
			SET_ADDRESS to 0 with 1
		usb_get_device_descriptor(udev, 8)
		usb_get_device_descriptor(udev, 18)
	descriptors_changed() --> goto re_enumerate:
		hub_port_logical_disconnect()
			kick_khubd()

And then:

hub_events()
	hub_port_connect_change()
		usb_disconnect()
			usb_disable_device()
		new device struct
		sets device state to Powered
		choose_address()
		hub_port_init() <-- no reset, but SET ADDRESS to 0 with 1, timeout!

The solution is to always reset the device in
hub_port_init() to put it in a known state.

Signed-off-by: Luben Tuikov <ltuikov@yahoo.com>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-02-17 10:30:24 -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 USB: cdc-acm: Adding second ACM channel support for Nokia N8 2011-02-04 12:38:14 -08:00
core USB: Reset USB 3.0 devices on (re)discovery 2011-02-17 10:30:24 -08:00
early usb: makefile cleanup 2010-10-22 10:22:07 -07:00
gadget USB, Mass Storage, composite, gadget: Fix build failure and memset of a struct 2011-02-04 12:38:14 -08:00
host USB: Fix trout build failure with ci13xxx_msm gadget 2011-02-04 12:38:14 -08:00
image SCSI host lock push-down 2010-11-16 13:33:23 -08:00
misc USB: uss720: remove duplicate USB device 2011-01-22 18:36:44 -08:00
mon Merge branch 'usb-next' into musb-merge 2010-12-16 10:05:06 -08:00
musb usb: musb: introduce api for dma code to check compatibility with usb request 2011-02-01 10:41:30 +02:00
otg USB: Fix trout build failure with ci13xxx_msm gadget 2011-02-04 12:38:14 -08:00
serial USB: Add Samsung SGH-I500/Android modem ID switch to visor driver 2011-02-17 10:30:23 -08:00
storage USB: usb-storage: unusual_devs entry for Coby MP3 player 2011-02-03 16:51:05 -08:00
wusbcore tree-wide: fix comment/printk typos 2010-11-01 15:38:34 -04:00
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.