51c48ce264
There are times, such as when the modem crashes, when we issue commands to clear the IPA hardware pipeline. These commands include a data transfer command that delivers a small packet directly to the default (AP<-LAN RX) endpoint. The places that do this wait for the transactions that contain these commands to complete, but the pipeline can't be assumed clear until the sent packet has been *received*. The small transfer will be delivered with a status structure, and that status will indicate its tag is valid. This is the only place we send a tagged packet, so we use the tag to determine when the pipeline clear packet has arrived. Add a completion to the IPA structure to to be used to signal the receipt of a pipeline clear packet. Create a new function ipa_cmd_pipeline_clear_wait() that will wait for that completion. Reinitialize the completion whenever pipeline clear commands are added to a transaction. Extend ipa_endpoint_status_tag() to check whether a packet whose status contains a valid tag was sent from the AP->command TX endpoint, and if so, signal the new IPA completion. Have all callers of ipa_cmd_pipeline_clear_add() wait for the pipeline clear indication after the transaction that clears the pipeline has completed. Signed-off-by: Alex Elder <elder@linaro.org> Acked-by: Willem de Bruijn <willemb@google.com> 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.