[alsa-devel] [PATCH] ASoC: da7219: check SRM lock in trigger callback

Pierre-Louis Bossart pierre-louis.bossart at linux.intel.com
Wed Feb 12 16:48:24 CET 2020


>> Thanks Ranjani. That information closes the door on the idea of playing
>> with the trigger order suggested earlier in the thread, so my guess is
>> that we really need to expose the MCLK/BCLK with the clk API and turn
>> them on/off from the machine driver as needed. I hope is that we don't
>> need the FSYNC as well, that would be rather painful to implement.
> 
> Am not going to make myself popular here. It's MCLK and FSYNC (or WCLK as it's
> termed for our device) that is required for SRM to lock in the PLL.
> 
> So far I've not found a way in the codec driver to be able to get around this.
> I spent a very long time with Sathya in the early days (Apollo Lake) looking at
> options but nothing would fit which is why I have the solution that's in place
> right now. We could probably reduce the number of rechecks before timeout in the
> driver but that's really just papering over the crack and there's still the
> possibility of noise later when SRM finally does lock.

Sorry, you lost me at "the solution that's in place right now". There is 
nothing in the bxt_da7219_max98357a.c code that deals with clocks or 
defines a trigger order?


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