linux/drivers/usb
Alan Stern af0bb5998a [PATCH] UHCI: use dummy TDs
This patch (as624) fixes a hardware race in uhci-hcd by adding a dummy
TD to the end of each endpoint's queue.  Without the dummy the host
controller will effectively turn off the queue when it reaches the end,
which happens asynchronously.  This leads to a potential problem when
new transfer descriptors are added to the end of the queue; they may
never get used.

With a dummy TD present the controller never turns off the queue;
instead it just stops at the dummy and leaves the queue on but inactive.
When new TDs are added to the end of the queue, the first new one gets
written over the dummy.  Thus there's never any question about whether
the queue is running or needs to be restarted.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-03-20 14:49:57 -08:00
..
atm [PATCH] UEAGLE : cmv name bug (was cosmetic) 2006-01-31 17:23:41 -08:00
class [PATCH] USB: convert a bunch of USB semaphores to mutexes 2006-03-20 14:49:55 -08:00
core [PATCH] USB: remove usbcore-specific wakeup flags 2006-03-20 14:49:56 -08:00
gadget [PATCH] USB: Zero driver: Removed duplicated code 2006-03-20 14:49:57 -08:00
host [PATCH] UHCI: use dummy TDs 2006-03-20 14:49:57 -08:00
image [PATCH] USB: convert a bunch of USB semaphores to mutexes 2006-03-20 14:49:55 -08:00
input [PATCH] usbhid: add error handling 2006-03-20 14:49:56 -08:00
media [PATCH] USB: convert a bunch of USB semaphores to mutexes 2006-03-20 14:49:55 -08:00
misc [PATCH] USB: convert a bunch of USB semaphores to mutexes 2006-03-20 14:49:55 -08:00
mon [PATCH] USB: convert a bunch of USB semaphores to mutexes 2006-03-20 14:49:55 -08:00
net [PATCH] USB: Pegasus: Linksys USBVPN1 support + cleanup 2006-03-20 14:49:56 -08:00
serial [PATCH] USB Serial: fix use-after-free bug in usb-serial core 2006-03-06 13:29:00 -08:00
storage [PATCH] USB: convert a bunch of USB semaphores to mutexes 2006-03-20 14:49:55 -08:00
Kconfig [PATCH] USB: add support for OCHI on AT91rm9200 2006-03-20 14:49:55 -08:00
Makefile [PATCH] USB: add support for OCHI on AT91rm9200 2006-03-20 14:49:55 -08:00
README Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
usb-skeleton.c [PATCH] USB: remove some left over devfs droppings hanging around in the usb drivers 2006-01-31 17:23:41 -08:00

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.