Re: [PATCH 3/3] mmc: sdhci-s3c: Add clk_(enable/disable) in runtime suspend/resume

["Heiko Stübner" <heiko@sntech.de>]

Am Donnerstag, 18. Oktober 2012, 11:36:03 schrieb Seungwon Jeon:
> On Thursday, October 18, 2012, Heiko Stübner <heiko@sntech.de> wrote:
> > Hi,
> > 
> > Am Donnerstag, 18. Oktober 2012, 04:04:42 schrieb Jaehoon Chung:
> > > Sorry, i didn't check this patch with s3c2416.
> > > (i didn't have the s3c2416 board.)
> > > If you have a problem, i think good that revert this patch for fixing
> > > your problem. Also, i will check and share the result.
> > 
> > After looking a bit more through the code, I don't think the problem is
> > 2416- specific but seems to be caused by the gpio card-detect code.
> > 
> > sdhci_s3c_gpio_card_detect_thread calls sdhci_s3c_notify_change which in
> > turn runs host->card_tasklet that seems to want to read stuff from the
> > card. But this path seems to be missing a runtime-pm wakeup.
> > 
> > I'm not yet sure what to add, especially, as tasklet_finish (called on
> > some occasions from tasklet_card) already has a runtime_pm_put call,
> > which would be unpaired in this code path.
> > 
> > As there also could be other Samsung platforms affected that use the
> > ext-gpio code, it's probably right to revert it for now. Or you see a
> > easy fix :-) .
> 
> Hi,
> 
> I think clock is disabled during bus transaction.
> I'll send a patch. Could you test it?

Sure, I'll test it.

Heiko


> > > On 10/17/2012 06:15 PM, Heiko Stübner wrote:
> > > > Hi,
> > > > 
> > > > Am Freitag, 14. September 2012, 11:08:51 schrieb Chander Kashyap:
> > > >> Perform clock disable/enable in runtime suspend/resume.
> > > >> 
> > > >> Signed-off-by: Chander Kashyap <chander.kashyap@linaro.org>
> > > > 
> > > > It seems this patch breaks my S3C2416 based machine with 3.7-rc1. I'm
> > > > not
> > > > 
> > > > yet sure why, but the only response I get is loop of:
> > > > 	mmc0: Timeout waiting for hardware interrupt.
> > > > 	mmc0: Internal clock never stabilised.
> > > > 	mmc0: Timeout waiting for hardware interrupt.
> > > > 	mmc0: Internal clock never stabilised.
> > > > 
> > > > This only happens on the hsmmc channel using the gpio-based card
> > > > detect and even prevents the card from beeing fully detected. The
> > > > other hsmmc channel using a permanent emmc seems to be working fine.
> > > > 
> > > > And of course, when I revert this patch everything works fine again.
> > > > 
> > > > I'll investigate further, but it'd be also ok if someone has a fix
> > > > for this before me :-) .
> > > > 
> > > > 
> > > > Heiko
> > > > --
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