mirror of
https://github.com/raspberrypi/linux.git
synced 2025-12-06 01:49:46 +00:00
3ab7c6549c
The xHC may commence Host Initiated Data Moves for streaming endpoints -
see USB3.2 spec s8.12.1.4.2.4. However, this behaviour is typically
counterproductive as the submission of UAS URBs in {Status, Data,
Command} order and 1 outstanding IO per stream ID means the device never
enters Move Data after a HIMD for Status or Data stages with the same
stream ID. For OUT transfers this is especially inefficient as the host
will start transmitting multiple bulk packets as a burst, all of which
get NAKed by the device - wasting bandwidth.
Also, some buggy UAS adapters don't properly handle the EP flow control
state this creates - e.g. RTL9210.
Set Host Initiated Data Move Disable to always defer stream selection to
the device. xHC implementations may treat this field as "don't care,
forced to 1" anyway - xHCI 1.2 s4.12.1.
Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>
Linux kernel
There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first.
In order to build the documentation, use make htmldocs or
make pdfdocs. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
Build status for rpi-6.1.y:
Build status for rpi-6.6.y:
Build status for rpi-6.12.y:
