On Wed, Dec 18, 2013 at 01:13:36PM +0800, Nicolin Chen wrote:
On Tue, Dec 17, 2013 at 10:50:02PM +0000, Mark Brown wrote:
I do think refcounting from both here and the bias level changes is going to be the most robust thing, that'd also avoid the need to peer into the CODEC register map.
I've tried count reference way to handle FLL enabler/disabler here before I sent this version. But the result shows the FLL would be never disabled in hw_free() because the refcount is accumulated to 2, one from hw_params() and the other from set_bias_level(PREPARE), which just made this patch meaningless to me.
Well, it gets the clocking configured early which was part of the goal I thought to ensure smoother startup.
So the reclocking with bypass checking seems to be the last resort I can figure out right here as the playback flow for 'aplay -Dhw:0 44k16bit.wav 48k24bit.wav' does need to reprogram the FLL during CODEC active.
That's the other bit. It should be possible for the machine driver to disable all outputs prior to reprogramming the FLL, though this will obviously glitch bypass paths. One way of doing it would be to have something that does the reprogramming but only if there is actually a change - that way the common case is unaffected.