linux/drivers/usb
David Brownell 30bf54e62a USB: PS3: Fix EHCI ISO transfer bug
This adds a workaround for an issue reported with ISO transfers
on some EHCI controllers, most recently with VIA KT800 and PS3
EHCI silicon.

The issue is that the silicon doesn't necessarily seem to be done
using ISO DMA descriptors (itd, sitd) when it marks them inactive.
(One theory is that the ill-defined mechanism where hardware caches
periodic transfer descriptors isn't invalidating their state...)
With such silicon, quick re-use of those descriptors makes trouble.
Waiting until the next frame seems to be a sufficient workaround.

This patch ensures that the relevant descriptors aren't available
for immediate re-use.  It does so by not recycling them until after
issuing the completion callback which would reuse them by enqueueing
an URB and thus (re)allocating ISO DMA descriptors.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Geoff Levand <geoffrey.levand@am.sony.com>
Cc: Masashi Kimoto <Masashi_Kimoto@hq.scei.sony.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-02-01 14:34:57 -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: add usbfs stubs for suspend and resume 2008-02-01 14:34:54 -08:00
gadget USB: Spelling fixes 2008-02-01 14:34:57 -08:00
host USB: PS3: Fix EHCI ISO transfer bug 2008-02-01 14:34:57 -08:00
image USB: Drop unnecessary continue in a few drivers 2008-02-01 14:34:51 -08:00
misc USB: Spelling fixes 2008-02-01 14:34:57 -08:00
mon USB: mon nopage 2008-02-01 14:34:56 -08:00
serial USB: Spelling fixes 2008-02-01 14:34:57 -08:00
storage USB: isd200: don't include <linux/ide.h> 2008-02-01 14:34:47 -08:00
Kconfig [ARM] USB: update to allow pxa27x ohci driver to support pxa3xx 2008-01-26 15:07:53 +00:00
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.