On Tue, Sep 25, 2012 at 11:29:58AM +0100, Russell King - ARM Linux wrote: > On Tue, Sep 25, 2012 at 12:48:16PM +0300, Felipe Balbi wrote: > > Hi, > > > > On Tue, Sep 25, 2012 at 10:21:18AM +0100, Russell King - ARM Linux wrote: > > > On Tue, Sep 25, 2012 at 12:11:14PM +0300, Felipe Balbi wrote: > > > > 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 ? > > > > > > What would cause a regression on beagleboard XM? I have not suggested > > > any change other than more investigation of the issue and a fuller patch > > > description - yet you're screaming (idiotically IMHO) that mere > > > investigation would break beagleboard. > > > > > > Well, if it's _that_ fragile, that mere investigation of this issue by > > > someone elsewhere on the planet would break your beagleboard, maybe it > > > deserves to be broken! > > > > why are you always so over the top like that ? This is just > > counter-productive to say the least. > > Because you are accusing me of potentially breaking your beagleboard > for merely suggesting further investigation and a better commit message. Where did I accuse you of anyting ? I just mentioned we experienced a regression with beagleboard XM when using pm_runtime_set_active(). here's my quote: > 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... To add extra info, here you go: We pinged Paul and asked if he had seen that before, he had no pointers... Because Documentation/power/runtime_pm.txt was using a mystruct->is_suspended flag, we just decided to follow the same "design" since no-one was able to suggest why pm_runtime_set_active() was breaking beagleXM nor how it was supposed to actually work. Reading the code: pm_runtime_set_active() would tell pm_runtime core the device is actually active by setting runtime_status to RPM_ACTIVE, thus the following pm_runtime_get_sync() wouldn't actually call runtime_resume() callback, but it would increment usage_counter. I can't see why this would fail on beagleXM, but it does and we'd like to hear in which situations this could fail... -- balbi
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