[alsa-devel] [PATCH 2/2] ASoC: DAPM - Make sure DAPM widget IO ops hold the component mutex.

[Liam Girdwood]

On Fri, 2012-03-09 at 17:26 +0000, Tabi Timur-B04825 wrote:
> On Tue, Mar 6, 2012 at 12:16 PM, Liam Girdwood <lrg at ti.com> wrote:
> > Currently not all DAPM widget IO ops are holding their component mutex
> > (codec or platform). Make sure this is now held for DAPM widget IO operations.
> >
> > Signed-off-by: Liam Girdwood <lrg at ti.com>
> 
> This patch breaks the P1022DS, which uses the WM8776 as a codec.  The
> MPC8610HPCD, which is identical to the P1022DS but uses the CS4270
> codec instead, works fine.
> 
> I'm guessing it's some kind of deadlock, because as soon as I start
> playback, the system halts.  Not even Ctrl-C works.
> 

Can you switch on the mutex debugging kernel config here.  I've just had
a quick look and the WM8776 and its not holding the codec mutex or
calling snd_soc_update_bits_locked() so it must deadlock via another
path.

Thanks

Liam