Peter Ujfalusi
72b745e3ad
The pcm_mutex is used to prevent concurrent execution of snd_pcm_ops callbacks. This works fine most of the cases but it can not handle setups when the same DAI is used by different rtd, for example: pcm3168a have two DAIs: one for Playback and one for Capture. If the codec is connected to a single CPU DAI we need to have two dai_link to support both playback and capture. In this case the snd_pcm_ops callbacks can be executed in parallel causing unexpected races in DAI drivers. By moving the pcm_mutex up to card level this can be solved while - hopefully - not breaking other setups. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Tested-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Link: https://lore.kernel.org/r/20190813104532.16669-1-peter.ujfalusi@ti.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.