On Mon, 30 Mar 2020 09:30:29 +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.
Thanks for the patches, all those look interesting and good to apply. But I'd like to get it reviewed by Kailang at first -- in case we might be playing with something untouchable.
Kailang, could you review this quickly?
Takashi
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
Documentation/sound/hd-audio/index.rst | 1 + Documentation/sound/hd-audio/models.rst | 2 - .../sound/hd-audio/realtek-pc-beep.rst | 129 ++++++++++++++++++ sound/pci/hda/patch_realtek.c | 49 ++----- 4 files changed, 139 insertions(+), 42 deletions(-) create mode 100644 Documentation/sound/hd-audio/realtek-pc-beep.rst
-- 2.25.2