[alsa-devel] [PATCH] ASoC: omap-mcbsp: Do not attempt to change DAI sysclk if stream is active

[Péter Ujfalusi]

On Friday 10 June 2011 14:28:55 Jarkko Nikula wrote:
> Attempt to change McBSP CLKS source while another stream is active is not
> safe after commit d135865 ("OMAP: McBSP: implement functional clock
> switching via clock framework") in 2.6.37.
> 
> CLKS parent clock switching using clock framework have to idle the McBSP
> before switching and then activate it again. This short break can cause a
> DMA transaction error to already running stream which halts and recovers
> only by closing and restarting the stream.
> 
> This goes more fatal after commit e2fa61d ("OMAP3: l3: Introduce
> l3-interconnect error handling driver") in 2.6.39 where l3 driver detects a
> severe timeout error and does BUG_ON().
> 
> Fix this by checking is the McBSP active in omap_mcbsp_dai_set_dai_sysclk
> before attempting to change any clocking configuration. This test should
> have been here just from the beginning anyway.
> 
> Signed-off-by: Jarkko Nikula <jhnikula at gmail.com>
> Cc: stable at kernel.org

Acked-by: Peter Ujfalusi <peter.ujfalusi at ti.com>