* Rafael J. Wysocki <rjw@xxxxxxx> wrote: > On Wednesday 25 February 2009, Ingo Molnar wrote: > > > > * Rafael J. Wysocki <rjw@xxxxxxx> wrote: > > > > > On Tuesday 24 February 2009, Linus Torvalds wrote: > > > > > > > > On Tue, 24 Feb 2009, Rafael J. Wysocki wrote: > > > > > > > > > > > The only safe way on x86 to shutdown a level triggered ioapic irq > > > > > > outside of irq context is for the driver to program the hardware to > > > > > > not generate an irq. > > > > > > > > > > Well, that changes things quite a bit, because it means we can't change the > > > > > suspend-resume sequence in a way we thought we could without fixing all > > > > > drivers first, but this is exactly what we'd like to avoid by changing the > > > > > core. > > > > > > > > Calling "disable_irq()" is perfectly fine. > > > > > > > > What is not possible on that broken IO-APIC (among other > > > > things) is to actually turn the interrupts off at the apic > > > > (ie the whole ->shutdown() thing). But that's not what we > > > > even want to do. What we care about is just disabling the > > > > interrupt from a drievr perspective. > > > > > > > > IOW, the patches I have seen are fine, and all the comments > > > > from Eric are just confusion about what we want done. > > > > > > Ah, OK. Thanks for the explanation, I got confused too. > > > > > > > WE DO NOT WANT TO TURN OFF THE IO-APIC. That may or may > > > > happen later, but that's totally unrelated to this whole > > > > "suspend_device_irq()" thing. > > > > > > Yeah. > > > > We definitely dont want to turn off x86 IO-APICs - the timer IRQ > > goes via one of them. > > No, we don't. At least not at this point. > > BTW, appended is the current (3rd) version of the $subject patch with some > of your comments taken into account. In particular, I did the following: > - moved [suspend|resume]_device_irqs() to a separate file (pm.c) > - fixed interrupt.h so that their headers are at a better place > - made enable_irq() clear IRQ_SUSPENDED > - made device_power_down() and device_power_up() call > suspend_device_irqs() and resume_device_irqs(), respectively, which > simplified the callers quite a bit (it changed the Xen code ordering, though, > but I _think_ it still should work). > > Please have a look. Looks good, thanks Rafael! Acked-by: Ingo Molnar <mingo@xxxxxxx> Ingo _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
