On Tue, Sep 25, 2012 at 10:12:28AM +0100, Russell King - ARM Linux wrote: > On Tue, Sep 25, 2012 at 11:31:20AM +0300, Felipe Balbi wrote: > > On Tue, Sep 25, 2012 at 09:30:29AM +0100, Russell King - ARM Linux wrote: > > > How is this happening? I think that needs proper investigation - or if > > > it's had more investigation, then the results needs to be included in > > > the commit description so that everyone can understand the issue here. > > > > > > We should not be resuming a device which hasn't been suspended. Maybe > > > the runtime PM enable sequence is wrong, and that's what should be fixed > > > instead? > > > > > > This sequence in the probe() function: > > > > > > pm_runtime_irq_safe(&pdev->dev); > > > pm_runtime_enable(&pdev->dev); > > > pm_runtime_get_sync(&pdev->dev); > > > > > > would enable runtime PM while the s/w state indicates that it's disabled, > > > and then that pm_runtime_get_sync() will want to resume the device. See > > > the section "5. Runtime PM Initialization, Device Probing and Removal" > > > in Documentation/power/runtime_pm.txt, specifically the second paragraph > > > of that section. > > > > that was tested. It worked in pandaboard but didn't work on beagleboard > > XM. Sourav tried to start a discussion about that, but it simply died... > > > > In any case, pm_runtime_get_sync() in probe will always call > > runtime_resume callback, right ? > > Well, if the runtime PM state says it's suspended, and then you enable > runtime PM, the first call to pm_runtime_get_sync() will trigger a resume > attempt. The patch description is complaining about resume events without > there being a preceding suspend event. > > This could well be why. that's most likely, of course. But should we cause a regression to beagleboard XM because of that ? Also, if you look into chapter 9 of the runtime_pm documentation, starting on line 822 you'll see documentation suggests the use of mystruct->is_suspended flag. -- balbi
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