Re: [PATCH 0/3] Properly fix headphone noise on the XPS 13 and other ALC256 devices

Takashi Iwai
2020-03-30T08:02:28Z

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
>