On Thu, 2009-11-26 at 20:52 +0530, Aggarwal, Anuj wrote:
-----Original Message----- From: Mark Brown [mailto:broonie@opensource.wolfsonmicro.com] Sent: Thursday, November 26, 2009 8:41 PM To: Aggarwal, Anuj Cc: 'Troy Kisky'; alsa-devel@alsa-project.org; linux-omap@vger.kernel.org; Arun KS Subject: Re: [alsa-devel] [PATCH] ASoC: AM3517: Fix AIC23 suspend/resume hang
On Thu, Nov 26, 2009 at 08:26:44PM +0530, Aggarwal, Anuj wrote:
driver, although I am not sure if the problem is in the audio driver. When tried to capture, using NFS as storage, it gives overrun error and
comes out with:
arecord: pcm_read:1617: read error: Input/output error
It happen always after ~20 sec, file size ~5MB. Tried with multiple configurations in arecord but no use. When tried: arecord -f cd /dev/null, it works fine. Same issue doesn't come too when I try to store the captured audio file on a MMC card.
Any idea what could be the problem? Why arecord goes for a toss after a single overrun error and why it is happening always after ~20 sec? Is there something which can be tried to narrow down the problem?
Sounds like you've narrowed the problem down to a performance issue with NFS writeout - it's probably having trouble keeping up with your I/O rate. This isn't 100% surprising with smaller systems, sometimes tuning the NFS configuration can resolve the issue but sometimes the hardware is just underspecified.
[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?
My two cents... could also try connecting the target directly to your host machine (using nfs), through a cross-cable (one with the Tx and Rx crossed). If no errors are seen, then it surely must be an attribution of network congestion.
Regards, Philby