linux-sg2042/drivers/usb
Linus Torvalds 09ca8adbe9 Revert "USB: don't explicitly reenable root-hub status interrupts"
This reverts commit e872154921.

Andrey Borzenkov reports that it resulted in a totally hung machine for
him when loading the OHCI driver.  Extensive netconsole capture with
SysRq output shows that modprobe gets stuck in ohci_hub_status_data()
when probing and enabling the OHCI controller, see for example

	http://lkml.org/lkml/2008/7/5/236

for an analysis.

The problem appears to be an interrupt flood triggered by the commit
that gets reverted, and Andrey confirmed that the revert makes things
work for him again.

Reported-and-tested-by: Andrey Borzenkov <arvidjaar@mail.ru>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <david-b@pacbell.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-06 10:27:25 -07:00
..
atm USB: Remove redundant dependencies on USB_ATM. 2008-05-02 10:25:57 -07:00
c67x00 usb/c67x00 endianness annotations 2008-06-04 08:06:01 -07:00
class USB: fix cdc-acm resume() 2008-07-03 18:20:36 -07:00
core Revert "USB: don't explicitly reenable root-hub status interrupts" 2008-07-06 10:27:25 -07:00
gadget USB: fsl_usb2_udc: fix recursive lock 2008-05-29 13:59:06 -07:00
host Revert "USB: don't explicitly reenable root-hub status interrupts" 2008-07-06 10:27:25 -07:00
image usb: replace remaining __PRETTY_FUNCTION__ occurrences 2008-04-24 21:16:48 -07:00
misc sisusbvga: Fix oops on disconnect. 2008-07-03 18:20:37 -07:00
mon usbmon: restore mmap 2008-04-24 21:16:43 -07:00
serial USB: adding comment for ipaq forcing number of ports 2008-07-03 18:20:38 -07:00
storage USB: mass storage: new id for US_SC_CYP_ATACB 2008-07-03 18:20:36 -07:00
Kconfig USB: add support for SuperH OHCI 2008-02-01 14:35:03 -08:00
Makefile USB: add Cypress c67x00 OTG controller HCD driver 2008-05-02 10:25:57 -07:00
README USB: fix directory references in usb/README 2007-11-28 13:58:34 -08:00
usb-skeleton.c USB: remove unnecessary type casting of urb->context 2008-04-24 21:16:55 -07:00

README

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.