New snd_hda driver came in.

Alexander Motin mav at
Sat Sep 13 17:08:57 UTC 2008


I have just committed my massive snd_hda driver update to the 8-CURRENT.

Because of using more clear and same time more functional codec parser 
new driver is able to handle more codecs, use them better then before 
and without most of previous quirks. All of tested codecs itself manage 
playback, record, input mixing and monitoring quite fine. In all of 
investigated trouble cases problem was found or in nonstandard codec 
usage or in incorrect codec configuration made by BIOS. Most of that 
cases could be fixed using device hints, some of which are already 
included to the driver.

New driver supports multiple codecs per HDA bus, multiple audio function 
groups per codec and multiple logical sound devices per audio function 
group. So don't worry when you get several PCM devices instead of one, 
it is normal. It is usual situation with powerful codecs to provide, for 
example, 3 PCM devices: one for 7.1 playback and main recording, one for 
headset and one for digital SPDIF I/O.

New driver implements Universal Audio Architecture (UAA) much better 
then previous one. Most information about recommended codec usage now 
taken from the codec configuration registers initialized by BIOS. User 
may alter that configuration using device hints to reconfigure logical 
audio devices to his needs in a very broad range up to the limits of the 
codec functionality.

New driver supports digital PCM playback and AC3 pass-through. I am not 
sure about completeness of this implementation, but I have several 
success stories including my own. Vchans subsystem does not support AC3 
pass-through so it had to be disabled for that devices at this moment.

New driver is ready for multichannel playback, but until our OSS is 
unable to use this it will just duplicate same stereo stream into all 
channel pairs.

New driver supports suspend/resume. I am unable to really test this part 
myself, but I have got several success stories.

Driver has very informative verbose boot messages. So if you have any 
questions or problems - enable and read them first.

Driver was actively discussed and tested on freebsd-multimedia@ mail list.

Alexander Motin

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