On Tuesday, July 08, 2014 02:12:59 PM Dmitry Torokhov wrote: > On Tue, Jul 08, 2014 at 11:06:17PM +0200, Rafael J. Wysocki wrote: > > On Tuesday, July 08, 2014 01:45:30 PM Dmitry Torokhov wrote: > > > On Tue, Jul 08, 2014 at 10:52:52PM +0200, Rafael J. Wysocki wrote: > > > > On Thursday, June 19, 2014 08:51:25 AM Li, Aubrey wrote: > > > > > When the wakeup attribute is set, the GPIO button is capable of > > > > > waking up the system from sleep states, including the "freeze" > > > > > sleep state. For that to work, its driver needs to pass the > > > > > IRQF_NO_SUSPEND flag to devm_request_any_context_irq(), or the > > > > > interrupt will be disabled by suspend_device_irqs() and the > > > > > system won't be woken up by it from the "freeze" sleep state. > > > > > > > > > > The suspend_device_irqs() routine is a workaround for drivers > > > > > that mishandle interrupts triggered when the devices handled > > > > > by them are suspended, so it is safe to use IRQF_NO_SUSPEND in > > > > > all drivers that don't have that problem. > > > > > > > > > > The affected/tested machines include Dell Venue 11 Pro and Asus T100TA. > > > > > > > > > > Signed-off-by: Aubrey Li <aubrey.li@xxxxxxxxxxxxxxx> > > > > > Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > > > > > > > OK > > > > > > > > Due to the lack of response (ie. no objections) and because the issue > > > > addressed by this patch is real, I'm queuing it up as a PM-related fix > > > > for 3.17. > > > > > > Please do not. The response is till the same: board code should make sure > > > that enable_irq_wake() does the right thing and keeps interrupts enabled. > > > > Which board code? That's nothing like that for the platforms in question. > > Then it needs to be written. Well, excuse me, but I don't get it. Why would I need to write any board code for an ACPI-based system? > > > It is wrong to patch drivers for this. > > > > Why is it? Only drivers know if they can handle incoming interrupts after > > having suspended their devices. > > The driver correctly used enable_irq_wake() to indicate that interrupt should > be a wakeup source, the now the core/board needs to make sure the interrupt > gets delivered to the driver properly. We should not be patching every driver > that uses enable_irq_wake() with IRQF_NO_SUSPEND. Interrupts that can wake up from the "freeze" sleep state need not be set up with enable_irq_wake() and the flag doesn't say "this is a wakeup interrupt". It says "do not suspend this interrupt, I can handle it after the device has been suspended" (as I said). And if it is OK for a driver to set IRQF_SHARED, it is equally OK for it to set IRQF_NO_SUSPEND, because, in fact, those two flags are related. > If you look at the earlier patch discussion Tegra folks managed to implement > this behavior just fine. I'm not sure whose idea it was that IRQF_NO_SUSPEND was not to be set by drivers, but it is not a correct one. I know why suspend_device_irqs() was introduced and I'm telling you this has nothing to do with setting up the IRQ chip to do system wakeup. And please grep for IRQF_NO_SUSPEND to see how drivers generally use it. Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
