Re: [PATCH v2] PM / sleep: prohibit devices probing during suspend/hibernation

From: Greg Kroah-Hartman
Date: Thu Nov 05 2015 - 21:08:19 EST


On Fri, Nov 06, 2015 at 03:04:10AM +0100, Rafael J. Wysocki wrote:
> On Thursday, November 05, 2015 04:09:57 PM Greg Kroah-Hartman wrote:
> > On Thu, Nov 05, 2015 at 11:38:23PM +0100, Rafael J. Wysocki wrote:
> > > On Monday, November 02, 2015 02:25:00 AM Rafael J. Wysocki wrote:
> > > > On Monday, October 19, 2015 11:54:24 PM Grygorii Strashko wrote:
> > > > > It is unsafe [1] if probing of devices will happen during suspend or
> > > > > hibernation and system behavior will be unpredictable in this case
> > > > > (for example: after successful probe the device potentially has a different
> > > > > set of PM callbacks than before [2]).
> > > > > So, let's prohibit device's probing in dpm_prepare() and defer their
> > > > > probes instead. The normal behavior will be restored in dpm_complete().
> > > > >
> > > > > This patch introduces new DD core APIs:
> > > > > device_defer_all_probes_enable()
> > > > > It will disable probing of devices and defer their probes.
> > > > > device_defer_all_probes_disable()
> > > > > It will restore normal behavior and trigger re-probing of deferred
> > > > > devices.
> > > > >
> > > > > [1] https://lkml.org/lkml/2015/9/11/554
> > > > > [2] https://lkml.org/lkml/2015/9/15/1039
> > > > > Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> > > > > Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
> > > > > Cc: Thierry Reding <thierry.reding@xxxxxxxxx>
> > > > > Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
> > > >
> > > > Greg, any objections against this one?
> > >
> > > Greg, if this isn't problematic, I'd still like to take it for v4.4.
> >
> > What? The merge window for new stuff closed a few weeks ago, how can
> > you add this for 4.4 when it needs to be in linux-next for a while
> > first?
>
> Well, it's not really scary and it was posted way before the merge window,
> but no one has had the time to look at it since then, apparently.
>
> Of course, I can queue it up for the next release too.

That would be best, thanks.

greg k-h
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