On Mon, 30 Jan 2017 09:22:59 +0000, Charles Keepax wrote:
On Sat, Jan 28, 2017 at 12:35:45AM +0100, Sergej Sawazki wrote:
Do not apply rate constraints in the startup() callback. The machine driver can change the sysclk and hence the supported frame rates in its hw_params(). This callback is unneeded since commit e369bd006fd6 ("ASoC: wm8741: Allow master clock switching").
This function should not be removed it is performing a useful function. If a sysclk has already been configured by the machine driver then we should inform user-space of the rates we can support from that clock. Without this that information is not available to user-space, so instead of user-space being able to resample appropriately it would just error out from hw_params.
Are you perhaps missing a call to clear the sysclk from your machine driver? Usually a dai_set_sysclk call with a rate of zero, also I find if it is a machine driver supporting multiple rates you are best to use ignore_pmdown_time on the DAI link, assuming the devices don't have long bring up times.
After clearing the sysclk, the codec should 'pretend' to support all rates, right? (no sysclk -> no rate constrains)
After applying rate constraints using snd_pcm_hw_constraint_list(...), what would be a clean way to remove the constraints from the rates parameter?
Thanks, Sergej