[alsa-devel] [PATCH 17/31] ASoC: tegra: call pm_runtime APIs around register accesses

Mark Brown broonie at kernel.org
Sat Nov 16 11:02:05 CET 2013

On Fri, Nov 15, 2013 at 01:54:12PM -0700, Stephen Warren wrote:
> From: Stephen Warren <swarren at nvidia.com>
> Call pm_runtime_get_sync() before all register accesses; the HW requires
> clocks to be running when accessing registers.
> This hasn't been needed to date, since all register IO was performed
> while playback was active, and hence the ASoC core had already called
> pm_runtime_get(). However, an imminent future commit will allocate and
> set up the FIFOs and routing during probe(), when that "protection"
> won't be in place.

Acked-by: Mark Brown <broonie at linaro.org>

However should we fix this at the regmap level in the same way that we
do for clocks?  That would need to be using _put_autosuspend() to avoid
being horrific.  Or alternatively should the driver be making the device
cache only when runtime PM is disabled?
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