mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-01-10 15:39:28 -05:00
3115be5513
For a BE link snd_soc_link_be_hw_params_fixup() is called by dpcm_be_dai_hw_params() to initialize the params before it passes them to __soc_pcm_hw_params(). Then __soc_pcm_hw_params() refines params to match the BE codec and passes that to snd_soc_dai_hw_params(). The second call of snd_soc_link_be_hw_params_fixup() within snd_soc_dai_hw_params() was overwriting the refined params with the original BE CPU DAI params. This would then lead to various problems, for example passing an invalid number of channels to the codec driver hw_params(), or enabling more AIF widgets on the codec than are actually mapped by TDM slots. These errors may not be noticed on a simple 1:1 link between one CPU DAI and one codec DAI, because most likely they have the same DAI config (though this is not necessarily true, for example if the CPU end has dummy TDM slots to achieve a desirable BCLK). For 1:N mappings there are likely to be multiple codecs using different subsets of the TDM slots and this overwriting of the refined params can cause incorrect configuration of each codec on the link. The erroneous extra call to the BE fixup function() was introduced by: commita655de808c("ASoC: core: Allow topology to override machine driver FE DAI link config.") at that time, the call to the BE fixup was already done by dpcm_be_dai_hw_params(), which was introduced several years earlier by: commit01d7584cd2("ASoC: dpcm: Add Dynamic PCM core operations.") The erroneous code has changed and moved to a different source file since the patch that introduced it, so this fix patch won't directly apply as a fix on top of code older than: commit8b4ba1d317("ASoC: soc-dai: fix up hw params only if it is needed") though it can be applied with some minor adjustment to code before that patch but after: commitaa6166c2ac("ASoC: soc-dai: mv soc_dai_hw_params() to soc-dai") On any tree older than that the code is in soc-pcm.c. Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com> Link: https://lore.kernel.org/r/20221104160252.166114-1-rf@opensource.cirrus.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.