Re: Regression in suspend to ram in 2.6.31-rc kernels

Christoph Hellwig
2009-09-03T23:23:44Z

On Fri, Sep 04, 2009 at 12:29:04AM +0200, Zdenek Kabelac wrote:
> Ok - another bisect game played - and unexpected winner is:
>
> (fat: add ->sync_fs)
>
> f83d6d46e7adf241a064a4a425e5cd8a8fd8925f
>
> Reverting this commit with current -rc8 kernel makes the system happy
> during the suspend/resume cycle. Obviously it has it price :) so just
> plain revert is probably not a good solution so the problem looks
> 'more serious' (fat is not the only fs with this patch) thus adding
> original author to this thread.

Note that when you rever this patch on a current kernel you do actually
get different behvaviour than when going back to before this commit.

In 2.6.30 we called ->write_super in the various sync functions and
then ->sync_fs, in 2.6.31-rc8 you would not call any syncing at all
anymore. I think this patch might just be a symptom for a situation
where the suspend code causes a sync and the mmc driver can't handle
it anymore.