[Sound-open-firmware] [PATCH] FIX: Add dma_stop when receive trigger stop cmd in host

[Liam Girdwood]

On Thu, 2018-05-03 at 09:10 +0800, zhigangw wrote:
> 
> On 2018年05月02日 21:09, Pan, Xiuli wrote:
> > 
> > 
> > On 5/2/2018 18:11, Liam Girdwood wrote:
> > > On Wed, 2018-05-02 at 09:56 +0000, Jie, Yang wrote:
> > > > > -----Original Message-----
> > > > > From: sound-open-firmware-bounces at alsa-project.org [mailto:sound-open-
> > > > > firmware-bounces at alsa-project.org] On Behalf Of Wu Zhigang
> > > > > Sent: Wednesday, May 2, 2018 5:34 PM
> > > > > To: sound-open-firmware at alsa-project.org
> > > > > Cc: Wu Zhigang <zhigang.wu at linux.intel.com>; Wu, Zhigang
> > > > > <zhigang.wu at intel.com>
> > > > > Subject: [Sound-open-firmware] [PATCH] FIX: Add dma_stop when receive
> > > > > trigger
> > > > > stop cmd in host
> > > > > 
> > > > > when ALSA lib detect xrun issue, it will send stop and start 
> > > > > command to DSP
> > > > > without reset. it will hit error in hds_dma_start, if we did not 
> > > > > add the
> > > > > dma_stop in
> > > > 
> > > > Small typo. Should be 'hda_dma_start'.
> > > > 
> > > > Others looks good to me.
> > > > 
> > > > 
> > > 
> > > Can someone confirm on BYT too.
> > 
> > BYT did not need this handler. The host dma for BYT is also GP-DMA and 
> > need to assign the DMA every host copy. When we trigger the host comp 
> > stop, there will no more host DMA.
> > This problem is only shown on the APL/CNL platforms.
> > 
> > BTW, this bug is hit by the ALSA pcm lib xrun recovery. When ALSA 
> > trace the dma pointer position, it will wrongly though the DSP is in 
> > xrun and try to recover it by STOP/START pattern.
> > Will the DSP be recovered from this kind of STOP/START?
> > 
> > Thanks
> > Xiuli
> 
> Actually, It should be added. Because we cannot confirm the ALSA lib 
> will not happen XRUN.
> In this situation, we have to recovered from this case.
> In the real environment, no one can confirm NO XRUN in ALSA.
> we have to make sure our DSP is rebust.
> 
> after fix this, there is still a xrun issue in the DSP.
> thanks

Ok, does this mean I should apply or is there another fix coming ?

Thanks

Liam