[alsa-devel] [PATCH] ASoC: AM3517: Fix AIC23 suspend/resume hang

[Aggarwal, Anuj]

> -----Original Message-----
> From: Mark Brown [mailto:broonie at opensource.wolfsonmicro.com]
> Sent: Thursday, November 26, 2009 9:00 PM
> To: Aggarwal, Anuj
> Cc: 'Troy Kisky'; alsa-devel at alsa-project.org; linux-omap at vger.kernel.org;
> Arun KS
> Subject: Re: [alsa-devel] [PATCH] ASoC: AM3517: Fix AIC23 suspend/resume
> hang
> 
> On Thu, Nov 26, 2009 at 08:52:08PM +0530, Aggarwal, Anuj wrote:
> 
> > [Aggarwal, Anuj] I am still surprised how this could be a NFS writeout
> issue
> > as we are seeing a consistent read/write rate of 2Mbps over tftp. When
> dd
> > command is used for read/write to further check NFS performance, 2Mbps
> for write and 4Mbps for read is observed.
> > Does that still mean nfs is the culprit? What could be tweaked in
> audio/network driver to avoid this problem, any suggestions?
> 
> There can also be issues with the way the data gets pushed into NFS
> interacting poorly - it's not just the raw data rate that's in play
> here, it's also things like how often the writes are done and how big
> they are.  Possibly also overhead from interacting with the ethernet
> chip but that's not normally an issue for anything modern.
> 
> The fact that this only happens when NFS is in use seems a fairly clear
> pointer to an interacton there.
[Aggarwal, Anuj] We were able to fine tune NFS and use arecord to capture
large files. But some more problems cropped up when tried to suspend /
resume. Basic playback is working fine wrt suspend/resume. But capture,
either tried independently or with playback, is creating a system wide
hang. I fixed that infinite-loop in resume path but I believe something
else needs cleanup too.
Any pointers? 
> 
> > [Aggarwal, Anuj] Any other utility to try capture which does error
> > recovering too?
> 
> Not for the console off the top of my head, and TBH I don't really know
> how good the error handling is in the various apps.  You could also try
> playing with the buffer size options in arecord.