I think the patch is for those systems which enable I2S clocks in
pcm_start instead
of pcm_prepare. It has no effect on systems already be able to turn on
clocks in
supply widgets or set_bias_level() function.
If the trigger type in the DAI link is TRIGGER_PRE, then the trigger
function of FE port
(component or CPU DAI) will be called before codec driver's trigger
function. In this
case we will be able to turn on the clock in time. However, if the
trigger type is
TRIGGER_POST, then the patch does not help because just like what you
said, codec
driver's trigger function is called first.
IIRC we recently did a change to deal with underflows. Ranjani, can you remind us what the issue was?
Hi Pierre,
Are you talking about the change in this commit acbf27746ecfa96b "ASoC: pcm: update FE/BE trigger order based on the command"?
We made this change to handle xruns during pause/release particularly on the Intel HDA platforms.
Thanks, Ranjani