7b041466ed
[ Upstream commit c1f848f12103920ca165758aedb1c10904e193e1 ] When the tdm lane mask is computed, the driver currently fills the 1st lane before moving on to the next. If the stream has less channels than the lanes can accommodate, slots will be disabled on the last lanes. Unfortunately, the HW distribute channels in a different way. It distribute channels in pair on each lanes before moving on the next slots. This difference leads to problems if a device has an interface with more than 1 lane and with more than 2 slots per lane. For example: a playback interface with 2 lanes and 4 slots each (total 8 slots - zero based numbering) - Playing a 8ch stream: - All slots activated by the driver - channel #2 will be played on lane #1 - slot #0 following HW placement - Playing a 4ch stream: - Lane #1 disabled by the driver - channel #2 will be played on lane #0 - slot #2 This behaviour is obviously not desirable. Change the way slots are activated on the TDM lanes to follow what the HW does and make sure each channel always get mapped to the same slot/lane. Fixes: 1a11d88f499c ("ASoC: meson: add tdm formatter base driver") Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Link: https://lore.kernel.org/r/20230809171931.1244502-1-jbrunet@baylibre.com Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Sasha Levin <sashal@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.