[SRU][B/C/D/unstable][PATCH 0/1] fix the pop noise for lenovo laptops with alc285

[Hui Wang]

BugLink: https://bugs.launchpad.net/bugs/1805079

[Impact]
Lenovo told us that some linux uers reported headphone noise on Lenovo's
website. After investigating, we found those Lenovo laptop mdoels all
have the codec of alc285, and we can reproduce the noise problem too.

[Fix]
Don't use the DAC of headphone, let headphone share the DAC with speaker,
the noise disappears.

[Test Case]
After applying this patch, we tested on Lenovo P52, P72, X1 carbon and X1
Yoda2, no noise anymore

[Regression Potential]
Low. This patch only apply to several lenovo machines, and after applying
this patch, both speaker and headphone still work very well.


Hui Wang (1):
  ALSA: hda/realtek - fix the pop noise on headphone for lenovo laptops

 sound/pci/hda/patch_realtek.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

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2.17.1