4c9d631adb
One quirk for certain versions of IPA is that endpoint DELAY mode does not work properly. IPA DELAY mode prevents any packets from being delivered to the IPA core for processing on a TX endpoint. The AP uses DELAY mode when the modem crashes, to prevent modem TX endpoints from generating traffic during crash recovery. Without this, there is a chance the hardware will stall during recovery from a modem crash. To achieve a similar effect, a GSI FLOW_CONTROLLED channel state was created. A STARTED TX channel can be placed in FLOW_CONTROLLED state, which prevents the transfer of any more packets. A channel in FLOW_CONTROLLED state can be either returned to STARTED state, or can be transitioned to STOPPED state. Because this operates on GSI channels, two generic commands were added to allow the AP to control this state for modem channels (similar to the ALLOCATE and HALT channel commands). Previously the code assumed this quirk only applied to IPA v4.2. In fact, channel flow control (rather than endpoint DELAY mode) should be used for all versions *starting* with IPA v4.2. Signed-off-by: Alex Elder <elder@linaro.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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.