1
linux/drivers/usb
David Brownell 79592b722e USB: ehci completes high speed ISO URBs sooner
This has some bugfixes for the EHCI driver's ISO transfer scanning
logic.  It was leaving ITDs and SITDs on the schedule too long, for
a few different reasons, which caused trouble.

  (a)	Look at all microframes for high speed transfers, not just
	the ones we expect to have finished.  This way transfers
	ending mid-frame will complete without needing another IRQ.
	This also minimizes bogus scheduling underruns (e.g. EL2NSYNC).

  (b)	When we encounter an ISO transfer (either speed, but this
	hits mostly at full speed) that's not yet been completed,
	immediately stop scanning; we've caught up to the hardware,
	no matter what other indications might say.

  (c)	Always clean up ITDs (for high speed transfers) when the HC
	is no longer running.

I'm not sure whether the last one has been observed before, but both
the others have been reported with "real world" audio and video code.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-01 14:35:02 -08:00
..
atm USB: Spelling fixes 2008-02-01 14:34:57 -08:00
class USB: Spelling fixes 2008-02-01 14:34:57 -08:00
core USB: Export suspend statistics 2008-02-01 14:35:00 -08:00
gadget USB: pxa2xx_udc: use debugfs not procfs 2008-02-01 14:35:01 -08:00
host USB: ehci completes high speed ISO URBs sooner 2008-02-01 14:35:02 -08:00
image USB: Drop unnecessary continue in a few drivers 2008-02-01 14:34:51 -08:00
misc USB: misc: legousbtower: semaphore to mutex 2008-02-01 14:35:02 -08:00
mon USB: mon nopage 2008-02-01 14:34:56 -08:00
serial USB: sierra driver - add update dtr logic 2008-02-01 14:35:00 -08:00
storage USB: usb/storage/initializers.c: fix signedness difference 2008-02-01 14:34:57 -08:00
Kconfig USB: add ehci-ixp bus glue 2008-02-01 14:35:02 -08:00
Makefile USB: always visit drivers/usb/misc/ 2007-10-12 14:55:26 -07:00
README USB: fix directory references in usb/README 2007-11-28 13:58:34 -08:00
usb-skeleton.c USB: usb-skeleton leaking locks on open 2007-10-12 14:55:26 -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.