Messages in this thread | | | Date | Thu, 5 Nov 2015 16:09:57 -0800 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH v2] PM / sleep: prohibit devices probing during suspend/hibernation |
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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@rowland.harvard.edu> > > > Cc: Rafael J. Wysocki <rjw@rjwysocki.net> > > > Cc: Thierry Reding <thierry.reding@gmail.com> > > > Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> > > > > 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?
I don't have any real objection to it, but I don't see how defering probing until "later" really solves anything, no one should be "changing pm callbacks" after some other probe succeeds, that sounds like someone just wants to have a broken system.
thanks,
greg k-h
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