[alsa-devel] acer ferrari one hda realtek - attempt to improve forte mic IC support

Alban Browaeys prahal at yahoo.com
Thu Jan 19 22:59:55 CET 2012

A lot of reports about aspire one issues lead me to think the mic IC
processing is the same as on this acer ferrari one 200.

Looking at alsa-driver-aspire_one-v1.09 assembly I see that it setup the
bdl entries to point to a capture buffer which it then split in two
buffers : namely mic and speaker .
This split happens by moving the first 32 bits to mic , the next 32 to
speaker , then to mic and so forth.
azx_pcm_hw formats is set to S16 LE.
I was wondering about the the 32 bits step between mic and speaker
buffer and ended up on azx_pcm_preapre where for the capture case
snd_hda_calc_stream_format is hardcoded a number of channels of 4.

My issue is I attempted the same trick and it seems I still miss
something . Ie the azx_dev->format passed in azx_setup_controller to
SD_FORMAT registry is incremented by 3 namely 0x33 . Though I still miss
half of each samples same as when I was passing runtime->channels ie 2
and 0x31. 

The codec is ALC272X ATI SB.

Best regards,
Alban Browaeys

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