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

[Greg Kroah-Hartman]

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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/