Kernel Bug Tracker – Bug 41342
Audio gain is massively higher in kernel 3.1
Last modified: 2011-08-24 11:30:55 UTC
The audio volume is much, much louder in 3.1-rc2 and -rc1 compared to kernel 3.0 and earlier for my card:
00:1b.0 Audio device: Intel Corporation 6 Series Chipset Family High Definition Audio Controller (rev 05)
Subsystem: Dell Device 050e
Flags: bus master, fast devsel, latency 0, IRQ 53
Memory at f1c00000 (64-bit, non-prefetchable) [size=16K]
Capabilities: <access denied>
Kernel driver in use: snd_hda_intel
Kernel modules: snd-hda-intel
Sound blasts out deafeningly unless I use alsamixer to adjust Master to zero (alsamixer says this is -64dB) and PCM to near to zero (eg a value like 27, ie -29dB).
Note that with kernel 3.0, adjusting PCM in alsamixer does not affect the sound gain, but in 3.1 it (luckily!) does. It's quite difficult to adjust the sound to a non-painful level using gnome-volume control because the gain is biased so high.
Please give alsa-info.sh output (run with --no-upload option).
Created attachment 69262 [details]
Thanks. The bug is that Master volume isn't linked with PCM volume, thus Master is just a noop in the new driver. The
Try the patch below.
Created attachment 69272 [details]
Thanks, that fixes it.
OK, the patch is included in sound git tree now. It'll be merged likely in 3.1-rc3.
A patch referencing this bug report has been merged in Linux v3.1-rc3:
Author: Takashi Iwai <firstname.lastname@example.org>
Date: Thu Aug 18 15:13:17 2011 +0200
ALSA: hda - Add "PCM" volume to vmaster slave list