[alsa-devel] Fixup set PCM/headphones volume from Master
I'm working on a kernel-level fixup for a set of hardware which uses a separate DAC for the "headphones" output. So far, I've gotten everything but the volume control working correctly. "PCM Playback Volume" controls the headphones volume since the same digital output drives both SPDIF and the analog headphones jack.
So, "PCM Playback Volume" should always equal "Master Playback Volume" when headphones are plugged in. (You can't insert both an SPDIF and headphones at the same time anyway, since they use the same jack, so there's no downside there.)
Here's where I could really use some help from people who know ALSA plumbing better than I do. It seems to me this should be possible by overriding the "Master Playback Volume" put function with one that finds the "PCM Playback Volume" control and sets the volume for both controls.
For some reason, I can't seem to access the PCM control from my master put function. Attempts to find it via snd_ctl_find_id or snd_ctl_find_numid result in kernel oops. There might be something simple I'm missing, or perhaps there is a better way to link the two volume controls?
It's HDA, Realtek ALC898. The headphones jack (analog 3.5mm output) (0x1b) is connected to a separate ESS DAC, which takes sound input from the PCM SPDIF output.
On Mon, 07 Nov 2016 22:36:21 +0100, David Jordan wrote:
It's HDA, Realtek ALC898. The headphones jack (analog 3.5mm output) (0x1b) is connected to a separate ESS DAC, which takes sound input from the PCM SPDIF output.
Note that the "Master" volume is a vmaster control, and usually it covers all DAC volume controls.
It'd be better if you provide a patch you're fighting with, together with alsa-info.sh output. Then other people can track the issue either with the real h/w or hda-emu.
Takashi
-- David Jordan david2@system76.com
On Mon, Nov 7, 2016, at 01:19 PM, Clemens Ladisch wrote:
David Jordan wrote:
I'm working on a kernel-level fixup for a set of hardware
What hardware? If HDA, which codec, and how is it connected?
Regards, Clemens
Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
I've attached both the patch I've been working with, and the alsa-info.txt for the hardware running an unmodified kernel.
I've attached the patch I've been working with.
And the alsa-info.txt
participants (3)
-
Clemens Ladisch -
David Jordan -
Takashi Iwai