On Mon, 30 Mar 2020 18:09:36 +0200, Thomas Hebb wrote:
The root cause of various pervasive audio problems on the XPS 13 9350/9360, mostly relating to the headphone jack, turns out to be an undocumented feature of the ALC256 and similar codecs that routes audio along paths not exposed in the HDA node graph. The best we've had so far to configure this feature is magic numbers provided by Realtek, none of which have fully fixed all issues.
This series documents the "PC Beep Hidden Register", which controls the feature and which I've reverse engineered using black box techniques, and uses my findings to hopefully fix the headphone issues on my XPS 13 once and for all.
Changes in v2:
- Change fixed value from 0x4727 to 0x5757, which should behave identically, on advice from Kailang.
Thomas Hebb (3): ALSA: doc: Document PC Beep Hidden Register on Realtek ALC256 ALSA: hda/realtek - Set principled PC Beep configuration for ALC256 ALSA: hda/realtek - Remove now-unnecessary XPS 13 headphone noise fixups
Now applied all three patches. The patch 2 had an incorrect Fixes tag (pointing to the stable commit instead of the original commit) so I corrected locally.
thanks,
Takashi