"Rafael J. Wysocki" <rjw@xxxxxxx> writes: > On Wednesday 06 May 2009, Kevin Hilman wrote: >> Arve Hjønnevåg <arve@xxxxxxxxxxx> writes: >> >> > On Tue, May 5, 2009 at 8:52 AM, Kevin Hilman >> > <khilman@xxxxxxxxxxxxxxxxxxx> wrote: >> >> Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> writes: >> >> >> >>> On Mon, 4 May 2009 17:27:04 -0700 Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx> wrote: >> >>> >> >>>> Interrupts that are flagged as wakeup sources via set_irq_wake() >> >>>> should not be disabled for suspend. >> >>>> >> >>> >> >>> Why not? >> >>> >> >> >> >> If an interrupt is a wakeup source, and it is disabled at the chip >> >> level, it will no longer generate interrupts, and thus no longer wake >> >> up the system. >> >> >> >> I'd be interested in hearing why wakeup interrupts should be disabled >> >> during suspend. > > That depends on whether or not they are used for anything else than wake-up. > >> >> [...] >> >> >>> >> >>> If this fixes some bug then please provide a description of that bug? >> >> >> >> The bug is that on TI OMAP, interrupts that are used for wakeup events >> >> are disabled by this code causing the system to no longer wake up. >> > >> > What do you do if the interrupt triggers right after your driver has >> > returned from its late suspend hook? >> >> If it's a wakeup IRQ, I assume you want it to prevent suspend. >> >> But I don't see how that can happen in the current code. IIUC, by the >> time your late suspend hook is run, your device IRQ is already >> disabled, so it won't trigger an interrupt that will be caught by >> check_wakeup_irqs() anyways. > > My understanding of __disable_irq() was that it didn't actually disable the > IRQ at the hardware level, allowing the CPU to actually receive the interrupt > and acknowledge it, but preventing the device driver for receiving it. Hmm, that's not normally what I think of as disabled. ;) > Does it work differently on the affected systems? Yes. __disable_irq() calls the irq_chip's disable method which is platform specific. On OMAP, this masks the IRQ at the hardware level preventing the CPU from seeing the interrupt. Kevin _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
