On Wed, 2009-08-19 at 00:18 +0100, epic wrote:
Several mic related bugs maybe solved with this patch or a derived one
1 -My internal-mic was not working and front jack mic sound was terrible (useless for headset mic).
2 -Detected offset level from inputs {line, mic}, this offset level increases with specific [boost] and/or [capture(NID 0x23)] gain.
- I just played around several days compiling and testing alsa with my
acer-alc268, checked all data communication with alc268, pin config etc. and tested different values for offset in pins.
- Found internal-mic comes alive with a 50% offset v_reference and mic
sound is much better.
*This patch applies/solves only for alc268 with option model=acer in alsa-base.conf, but i think the others acer-alcxxx bugs maybe solved in the same way.
changing PIN_VREF80 to PIN_VREF50 at NID 0x18 mic NID 0x19 internal-mic NID 0x1a line-in (not tested)
*Don't know what can happen to other acer-alcxxx, so i only patched acer-alc268. But this patch solved my mic-internal issue and most important for me now i can use a headset mic.
*It remains a level offset, lower than before, but mic is usable, the level is showed in the pictures.
I have acer too (Aspire 5720)
And I also see high DC offsets on both internal and external mics (and sound quality of internal mic is very bad)
But doesn't help here. I have set the voltage on the corresonding pins using hda-verb, and I an hardly notice any difference (maybe the internal mic is already destroyed by high voltage...)
sudo ./hda-verb /dev/snd/hwC0D0 0x19 SET_PIN_WIDGET_CONTROL 0x21
(this one for internal mic)
Best regards, Maxim Levitsky