[alsa-devel] [PATCH 1/2] ASoC: uda1380: make driver more powersave-friendly
anarsoul at gmail.com
Sat Aug 28 11:07:54 CEST 2010
В сообщении от 28 августа 2010 11:56:36 автор Mark Brown написал:
> On Sat, Aug 28, 2010 at 10:49:35AM +0300, Vasily Khoruzhick wrote:
> > Disable some codec modules in standby mode, completely disable
> > codec in off mode to save some power.
> > Fix suspend/resume: mark mixer regs as dirty on resume to
> > restore mixer values, otherwise driver produces no sound
> > (master is muted by default).
> This sounds like there's a pre-existing bug where the register cache
> defaults don't correspond to the chip defaults. In general we always
> keep the initial chip defaults for user visible controls in the driver
> and let the application layer set the values it wants. This avoids
> having to worry about defaults being inappropriate for some systems (eg,
> volumes far too loud or bad output path selection) - normally the chip
> defaults will be reasonable for first power up.
It seems that you misunderstood me, chip defaults are ok for first power up,
but resume is not first power up and codec defaults differ from cache, so we
want to sync cache with codec regs on resume, but it is not possible to sync
mixer regs until i2s clock is not applied, so we just mark them as dirty to
sync them later (just before playback, when i2s clock is already applied)
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