[alsa-devel] [PATCH] ALSA: ASoC: cs4270: move power management hooks to snd_soc_codec_device
daniel at caiaq.de
Wed Aug 5 20:50:43 CEST 2009
On Wed, Aug 05, 2009 at 07:37:00PM +0100, Mark Brown wrote:
> On Wed, Aug 05, 2009 at 08:30:36PM +0200, Daniel Mack wrote:
> > Power management for the cs4270 codec is currently implemented as part
> > of the i2c_driver struct. The disadvantage of doing it this way is that
> > the callbacks registered in the snd_soc_card struct are called _before_
> > the codec's callbacks.
> > That doesn't work, because the snd_soc_card callbacks will most likely
> > switch down the codec's power domains or pull the reset GPIOs, and
> > hence make the i2c communication bail out.
> > Fix this by binding the suspend and resume code to the
> > snd_soc_codec_device driver model.
> You should leave the suspend and resume functions for I2C but have them
> call the snd_soc_suspend_device() and snd_soc_resume_device() callbacks
> in the core (which do nothing but will in future ensure that the entire
> card goes down when one of the components goes down to make sure we are
> always able to communicate with all the card components). The actual
> suspend and resume actions should be moved as you have done.
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