mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2025-01-10 23:20:05 +00:00
5cb7df2b2d
Gary reports that with recent kernels, he notices more xHCI driver warnings: xhci_hcd 0000:03:00.0: WARN Successful completion on short TX: needs XHCI_TRUST_TX_LENGTH quirk? We think his Etron xHCI host controller may have the same buggy behavior as the Fresco Logic xHCI host. When a short transfer is received, the host will mark the transfer as successfully completed when it should be marking it with a short completion. Fix this by turning on the XHCI_TRUST_TX_LENGTH quirk when the Etron host is discovered. Note that Gary has revision 1, but if Etron fixes this bug in future revisions, the quirk will have no effect. This patch should be backported to kernels as old as 2.6.36, that contain a backported version of commit 1530bbc6272d9da1e39ef8e06190d42c13a02733 "xhci: Add new short TX quirk for Fresco Logic host." Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Reported-by: Gary E. Miller <gem@rellim.com> Cc: stable@vger.kernel.org
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.