[alsa-devel] [PATCH] ALSA: hda: Add speaker pin to automute Acer Aspire 8943G

Raymond Yau superquad.vortex2 at gmail.com
Sat Oct 16 09:06:17 CEST 2010

2010/10/14 Valentine Sinitsyn <valentine.sinitsyn at gmail.com>

> Hi David,
> First of all, thank you for your work on subwoofer issues.

it seem that acer aspire 8943g has 5.1 speakers according to acer web site

with five built-in speakers and one subwoofer supporting low-frequency


alc670 is a 6 channels codec with [Audio Output] at nodes 0x02, 0x03 and


Seem that your Lenovo are not using ALC670,
Nope it doesn't. It is Lenovo Y550P with ALC272, and in my system, the
subwoofer is connected at pin 0x17. I'm not at it at the moment, but I can
send alsa-info.sh later if it is of any interest.

 ALC272 is just a four channels codec ,

If you look at the block diagram (page 5) of alc272 datasheet , the mono-out
(Port H) pin 0x17 has no volume control , and it is connected through 0x0f
to [Audio Output] node 0x02.

This is quite different from STAC9200 which has a volume control for the
mono-out widget

The beep-in and the beep generator can connected to 0x0f through [Audio
Mixer] 0x0b
this mean that the driver cannot assume that master-mono must be connected
to a subwoofer.

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