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 ("hub_wq").
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.
Select Git revision
usb
-
-
- Open in your IDE
- Download source code
- Download this directory
YD Tseng
authored and
Greg Kroah-Hartman
committed
xHCI host controllers can have both USB 3.1 and 3.0 extended speed
protocol lists. If the USB3.1 speed is parsed first and 3.0 second then
the minor revision supported will be overwritten by the 3.0 speeds and
the USB3 roothub will only show support for USB 3.0 speeds.
This was the case with a xhci controller with the supported protocol
capability listed below.
In xhci-mem.c, the USB 3.1 speed is parsed first, the min_rev of usb3_rhub
is set as 0x10. And then USB 3.0 is parsed. However, the min_rev of
usb3_rhub will be changed to 0x00. If USB 3.1 device is connected behind
this host controller, the speed of USB 3.1 device just reports 5G speed
using lsusb.
00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
00 01 08 00 00 00 00 00 40 00 00 00 00 00 00 00 00
10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
20 02 08 10 03 55 53 42 20 01 02 00 00 00 00 00 00 //USB 3.1
30 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
40 02 08 00 03 55 53 42 20 03 06 00 00 00 00 00 00 //USB 3.0
50 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
60 02 08 00 02 55 53 42 20 09 0E 19 00 00 00 00 00 //USB 2.0
70 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
This patch fixes the issue by only owerwriting the minor revision if
it is higher than the existing one.
[reword commit message -Mathias]
Cc: <stable@vger.kernel.org>
Signed-off-by: 
YD Tseng <yd_tseng@asmedia.com.tw>
Signed-off-by: 
Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: 
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Code owners
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