On Thu, 6 Sep 2012 12:57:46 +0530 "Shilimkar, Santosh" <santosh.shilimkar@xxxxxx> wrote: > On Thu, Sep 6, 2012 at 12:32 PM, NeilBrown <neilb@xxxxxxx> wrote: > > On Thu, 6 Sep 2012 11:18:09 +0530 "Shilimkar, Santosh" > > <santosh.shilimkar@xxxxxx> wrote: > > > >> On Thu, Sep 6, 2012 at 8:35 AM, NeilBrown <neilb@xxxxxxx> wrote: > >> > On Mon, 3 Sep 2012 22:59:06 -0700 "Shilimkar, Santosh" > >> > <santosh.shilimkar@xxxxxx> wrote: > > > >> >> After thinking bit more on this, the problem seems to be coming > >> >> mainly because the gpio device is runtime suspended bit early than > >> >> it should be. Similar issue seen with i2c driver as well. The i2c issue > >> >> was discussed with Rafael at LPC last week. The idea is to move > >> >> the pm_runtime_enable/disable() calls entirely up to the > >> >> _late/_early stage of device suspend/resume. > >> >> Will update this thread once I have further update. > >> > > >> > This won't be late enough. IRQCHIP_MASK_ON_SUSPEND takes effect after all > >> > the _late callbacks have been called. > >> > I, too, spoke to Rafael about this in San Diego. He seemed to agree with me > >> > that the interrupt needs to be masked in the ->suspend callback. any later > >> > is too late. > >> > > >> Thanks for information about your discussion. Will wait for the patch then. > >> > >> Regards > >> santosh > > > > I already sent a patch - that is what started this thread :-) > > > > I include it below. > > You said "The patch doesn't seems to be correct" but didn't expand on why. > > Do you still think it is not correct? I wouldn't be surprised if there is > > some case that it doesn't handle quite right, but it seems right to me. > > > Sorry I though you were talking about moving the "Checking wakeup interrupts" > bit early as discussed on the follow up of alternate suggested patch to make > use of IRQCHIP_MASK_ON_SUSPEND. > > I think we need to fix the issue seen with ' IRQCHIP_MASK_ON_SUSPEND' > patch. That is at least the expected way to manage suspend and wakeup > irq masks for a IRQCHIP. That is what I thought at first too. But when talking to Rafael he said that IRQCHIP_MASK_ON_SUSPEND was intended mainly for clock interrupts. For other less fundamental interrupts, doing the mask/unmask in suspend/resume callbacks is sufficient and simpler... and actually works. IRQCHIP_MASK_ON_SUSPEND is currently used by precisely two drivers: arch/arm/mach-omap2/omap-wakeupgen.c and drivers/mfd/pm8xxx-irq.c which suggests that it isn't widely used and quite possibly doesn't actually work in general. The pm8xxx-irq doesn't seem to do runtime pm, so maybe it manages to work for that reason. The omap-wakeupgen code is beyond my current understanding, but it seems like it might be the sort of special case that IRQCHIP_MASK_ON_SUSPEND is intended for... Maybe we need to start a new thread and pester Rafael or Thomas Gleixner to either explain what is intended for this case, or to fix IRQCHIP_MASK_ON_SUSPEND so that it can be used in general. NeilBrown
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