On Mon, 2009-05-04 at 20:49 +0800, Jeff wrote:
> How to work around the priority inversion issue? Your much help is
> appreciated. Thanks.

Below was my e-mail describing the issue and the work around.  Please
note that this is only a work around.

The freeze problem is caused by priority between the I/O thread
and DSPLINK_DPC_2.  The DSPLINK_DPC_2 is blocked when the GStreamer I/O
thread runs.  The audio/video thread (both has higher priority then I/O
thread) depends on the DSPLINK_DPC_2.   As a result, both audio and
video display thread are blocked while I/O thread runs.  We  can avoid
the issue by lowering the I/O thread priority using nice.

Replace gstreamer_demo/shared/run_pipe.sh,

$CMD
 
with

nice -n 15 $CMD

Regards,

Steve

> 
> Jeff
> 
> -----邮件原件-----
> 发件人: Steve Chen [mailto:[email protected]] 
> 发送时间: 2009年5月4日 20:50
> 收件人: Jeff
> 抄送: Davinci-Linux-Source
> 主题: Re: 答复: about audio driver stalls.
> 
> On Mon, 2009-05-04 at 20:17 +0800, Jeff wrote:
> > Did you no see stalls while playing clip with audio & video using ALSA on
> > MVL 2.6.18? When I switched to MVL 2.6.18, I found this bug is not fixed.
> 
> There is a priority inversion issue with pre-releases version of
> GStreamer/DSPLink TI gave me.  Once I worked around the issue, GStreamer
> worked fine on DM6446 EVM.  On DM355, GStreamer never worked very well
> for me.  For one thing, I play video/audio from NFS.  The dm9000 on the
> DM355 EVM has really bad Ethernet performance (something like 25-28 Mbps
> with netperf).  Not to mention the driver is copying Ethernet data with
> CPU in the ISR which does not help interrupt latency.
> 
> > Did you change the source code of MVL 2.6.18? I suspected that it was
> caused
> > by EDMA setting. But I am not sure it.
> 
> There has been some EDMA updates from MVL 2.6.10 to MVL 2.6.18.  Audio
> driver is of course completely redone.  However, the dm9000 and video
> drivers are largely unchanged.
> 
> Regards,
> 
> Steve
> 
> > 
> > BR
> > Jeff
> > 
> > -----邮件原件-----
> > 发件人: Steve Chen [mailto:[email protected]] 
> > 发送时间: 2009年5月4日 19:14
> > 收件人: Jeff
> > 抄送: Davinci-Linux-Source
> > 主题: Re: about audio driver stalls.
> > 
> > On Mon, 2009-05-04 at 06:01 -0500, Steve Chen wrote:
> > > On Mon, 2009-05-04 at 18:34 +0800, Jeff wrote:
> > > > All,
> > > > 
> > > >  
> > > > 
> > > > I found there was a serious stalls bug from DAVINCI OSS/ALSA audio
> > > > driver & EDMA driver. I have asked many times but I have no gotten any
> > > > news from forum as well as TI support team. Any help is appreciated.
> > > 
> > > Don't know much about DaVinci OSS, but I tested DaVinci ALSA
> > > (dm6446/6467/355 and da830) quite extensively and I have not noticed any
> > > kernel issues.  The only issues I noticed is periodic frame/audio pulse
> > > using GStreamer with MV 2.6.18 kernel.  The problem was traced back to
> > > the application.  I used aplay/record, wavplay/rec, sox, and TI's decode
> > > (which plays audio and video).  All seems to work for me.
> > 
> > Actually, I need to correct myself.  GStreamer and TI's decode demo has
> > some performance issuess on the dm355 EVM. 
> > 
> > 
> > > 
> > > Regards,
> > > 
> > > Steve
> > > 
> > > > 
> > > >  
> > > > 
> > > > BR,
> > > > 
> > > > Jeff
> > > > 
> > > >  
> > > > 
> > > > 
> > > > _______________________________________________
> > > > Davinci-linux-open-source mailing list
> > > > [email protected]
> > > > http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
> > > 
> > > 
> > > _______________________________________________
> > > Davinci-linux-open-source mailing list
> > > [email protected]
> > > http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
> > 
> > 
> > 
> 
> 
> 


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