[alsa-devel] [PATCH 1/2] OMAP3: MCBSP: Suspend/resume failure fix
anuj.aggarwal at ti.com
Mon Nov 30 12:50:45 CET 2009
> > Looking at the very original patch, I don't know how things could get
> > into deep sleep by disabling the fclk only... need to disable the iclk
> > also. In threshold mode, HW autogates the iclk, so you may be just
> > "lucky".
> [Anuj] No, I am not :(. I had to modify the original patch to include
> the disable part for the ICLK too. Without that, I was not able to hit
> I will try to do some further regression on OMAP3 EVM and post my
> findings. As of now, audio is working fine with these patches + ICLK
[Aggarwal, Anuj] After further testing, I found that there is some
problem in the capture path. While capturing in background, if I tried
to do suspend, capture fails after a few seconds giving;
arecord: pcm_read:1617: read error: Input/output error
This I was discussing in another thread (*) for AIC23/AM3517 on NFS but now
I realized after finishing my tests that this behavior is common for
both omap3530/twl4030 and am3517/aic23. Moreover, the problem doesn't
depend on the underlying file system - both NFS and ramdisk produce the
To make matter worse, if suspend/resume is tried while audio
loopback is running, system just hangs. Even telnet to the evm doesn't work.
So the audio capture path, from suspend/resume point of view, definitely
needs some more time.
I will continue debugging at my end. But pointers are always welcome.
> > One may want to be aware of this also:
> > http://git.kernel.org/?p=linux/kernel/git/tmlind/linux-omap-
> > I think it's an undocumented feature.
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