010c050fe9
By acking a received message we tell the DSP that we have processed the message (reply or notification) and we are open to receive a new one. The original implementation did this in a common code after the received message got handled as reply or notification. With right timing this opens up a small window when we have processed the reply and let the other thread proceed to send a new message to the DSP, which is allowed as the DSP is free to receive message. But when the message is received and processed by the DSP and it wants to send a reply it will still see that the previous message has not been acked, so it fails to send a reply. Later the first reply got acked by the kernel, but it is too late and the in-flight message got a timeout due to firmware not responding (which it tried, but could not). Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com> Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com> Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com> Reviewed-by: Rander Wang <rander.wang@intel.com> Link: https://lore.kernel.org/r/20221018124008.6846-5-peter.ujfalusi@linux.intel.com Signed-off-by: Mark Brown <broonie@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.