[PATCH 0/1][SRU][OEM-5.10/H/U] Fix CS8409 crack sound on Bullseye
You-Sheng Yang
vicamo.yang at canonical.com
Mon Apr 26 03:54:17 UTC 2021
BugLink: https://bugs.launchpad.net/bugs/1924997
[Impact]
On a few CS8409 installed platforms, there are crack sounds when playing
audio with output volume set to 100%.
[Fix]
The hardware is not capable of generating smooth audio output at the
maximum volume that codec chip can be configured. A fix proposed to lower
the maximum output volume using CS8409 equalizer.
[Test Case]
Use GNOME Settings / Sound Settings, set volume to 100%, play test
audio for both right and left channels; set volume back to 70%, and
repeat the same to compare to differences. While we don't have acoustic
lab to perform precise measurements, the result was confirmed by
partner.
[Where problems could occur]
This is to add a preconfigured, equalizer driver default values. This
will introduce non-uniformed frequency response in comparison to that in
the hardware preset. The net effect observable to general users is a
lower maximum output volume. For those Hi-Fi users, audio output always
takes additional calibration via extra software like ALSAEqual and/or
hardware.
[Other Info]
By SRU we skipped a couple of refactoring changes in asound upstream
tree, so additional changes to the original patch are required to
backport.
Stefan Binding (1):
UBUNTU: SAUCE: ALSA: hda/cirrus: Use CS8409 Equalizer to fix abnormal
sounds on Bullseye
sound/pci/hda/patch_cirrus.c | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
--
2.30.2
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