[alsa-devel] [PATCH 3/3] ASoC: core: Change power state before rechecking endpoint

[Vinod Koul]

On Mon, Nov 23, 2015 at 07:13:12PM +0100, Lars-Peter Clausen wrote:
> On 11/23/2015 06:28 PM, Vinod Koul wrote:
> > On Mon, Nov 23, 2015 at 05:06:41PM +0100, Lars-Peter Clausen wrote:
> >> On 11/23/2015 04:52 PM, Vinod Koul wrote:
> >>> From: Jeeja KP <jeeja.kp at intel.com>
> >>>
> >>> For DAPM resume, we should first change the power state of the
> >>> card and then recheck the endpoints. This ensures the dapm is
> >>> resumed first and then userspace can resume the streams.
> >>
> >> The problem is that DAPM uses the userspace state to decide whether to power
> >> up or not. So this change won't work, it will keep the endpoints suspended.
> > 
> > Well our observation are bit different...
> > 
> > When testing with aplay and suspending the system the DAPM was suspending
> > fine and then alsa suspends PCMs, but on resume the DAPM is resumed last and
> > the PCMs first, due to which the devices start underun!
> > The DAPM should be resumed first and then we should allow userspace access
> > (PCM resume from aplay)
> > 
> > The change of order here helps in that
> 
> Sorry, overlooked something. We go to D2 earlier on and DAPM only is
> suspended when the state is D3 and not only when it is not in D0.

No issues

> Patch looks good.
> 
> Reviewed-by: Lars-Peter Clausen <lars at metafoo.de>

Thanks for the review

-- 
~Vinod