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| author | Jaroslav Kysela <perex@perex.cz> | 2023-02-02 12:20:13 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-10 11:33:20 +0300 |
| commit | f716ca292a7d1808d4135273bbdca093da195831 (patch) | |
| tree | e67e6ae90178f75833bf4b8be447679d04946567 /include/asm-generic | |
| parent | 355d109fb6b74791ca85403fad9b4d2ff6c588af (diff) | |
| download | linux-f716ca292a7d1808d4135273bbdca093da195831.tar.xz | |
ALSA: hda: Fix the control element identification for multiple codecs
[ Upstream commit d045bceff5a904bd79d71dede9f927c00ce4906f ]
Some motherboards have multiple HDA codecs connected to the serial bus.
The current code may create multiple mixer controls with the almost
identical identification.
The current code use id.device field from the control element structure
to store the codec address to avoid such clashes for multiple codecs.
Unfortunately, the user space do not handle this correctly. For mixer
controls, only name and index are used for the identifiers.
This patch fixes this problem to compose the index using the codec
address as an offset in case, when the control already exists. It is
really unlikely that one codec will create 10 similar controls.
This patch adds new kernel module parameter 'ctl_dev_id' to allow
select the old behaviour, too. The CONFIG_SND_HDA_CTL_DEV_ID Kconfig
option sets the default value.
BugLink: https://github.com/alsa-project/alsa-lib/issues/294
BugLink: https://github.com/alsa-project/alsa-lib/issues/205
Fixes: 54d174031576 ("[ALSA] hda-codec - Fix connection list parsing")
Fixes: 1afe206ab699 ("ALSA: hda - Try to find an empty control index when it's occupied")
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20230202092013.4066998-1-perex@perex.cz
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'include/asm-generic')
0 files changed, 0 insertions, 0 deletions