[SRU][R][PATCH 0/1] ALSA: hda/tas2781 Audio Fix for the front-right speacker

[AceLan Kao]

From: "Chia-Lin Kao (AceLan)" <acelan.kao at canonical.com>

BugLink: https://bugs.launchpad.net/bugs/2149770

[Impact]
Audio is still wrong on some HP systems with TAS2781 SPI audio.

LP#2141639 fixed the earlier case where the front-right speaker had no
audio because firmware download was skipped during SPI probe. That fix
is already in linux-oem-6.17.

But the same TAS2781 SPI path still has problems on other HP systems.
After the earlier fix, the right speaker may work but sound is still
abnormal, unclear, or lower than the left speaker.

This hits multiple HP systems and shows 100% repro with:
$ speaker-test -c 2 -l 1 -t wav

The issue is in TAS2781 SPI calibration and firmware handling, not only
the old reset check from LP#2141639.

[Fix]
Backport the upstream TAS2781 follow-up fixes needed for HP SPI systems.

  ALSA: hda/tas2781: Fix sound abnormal issue on some SPI device
  upstream: 055e3fcc66caee8ae470c98e06120b494c95525b
  upstream version: not tagged yet in this tree, merged in linux-next

These patches extend the earlier LP#2141639 fix. They initialize the SPI
TAS2781 path correctly for HP systems, fix catalog/chip setup, use the
right bulk read path for SPI calibration data, add missing safety checks,
and include the calibration update used to avoid low or unclear
right-speaker output.

Together they address the remaining TAS2781 SPI issues seen on HP systems
after LP#2141639.

[Test Plan]
On an affected HP system with TAS2781 SPI audio:

1. Boot the patched kernel.
2. Run:
   $ speaker-test -c 2 -l 1 -t wav
3. Listen to left and right speakers separately.
4. Check kernel log for TAS2781 errors:
   $ dmesg | grep -i tas2781

Without these patches:
- the old LP#2141639 fix may restore audio on some systems only
- on other systems the right speaker may still sound unclear, abnormal, or
  lower than the left one

With these patches:
- both speakers produce audio
- the right speaker no longer shows the abnormal SPI calibration behavior
  reported in STELLA-3075
- no new TAS2781 firmware or calibration errors show up in dmesg

[Where problems could occur]
These changes touch the TAS2781 HDA/SPI path, TAS2781 calibration handling,
and runtime PM helpers.

If the SPI calibration path is wrong, HP systems with TAS2781 could still
get bad speaker balance, distorted output, or no audio on one channel.

If the chipid or catlogid setup is wrong, firmware or calibration data may
not be loaded correctly for SPI devices.

If the runtime PM related changes are wrong, audio init or resume could
fail and the codec may not be available after boot or resume.

Regression would show up as TAS2781 probe failures, missing
firmware/calibration behavior, no sound from one speaker, or lower/unclear
output from one side.

Baojun Xu (1):
  ALSA: hda/tas2781: Fix sound abnormal issue on some SPI device

 sound/hda/codecs/side-codecs/tas2781_hda_spi.c | 1 +
 sound/soc/codecs/tas2781-fmwlib.c              | 7 +++----
 2 files changed, 4 insertions(+), 4 deletions(-)

-- 
2.53.0