Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx> writes: > "Rafael J. Wysocki" <rjw@xxxxxxx> writes: > >> On Wednesday 06 May 2009, Kevin Hilman wrote: [...] >>> >>> [...] >>> >>> >>> >>> >>> 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. > >> 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. Looking at x86, the i8259 disable hook also seems to mask the IRQ at the PIC level. The various IO-APIC irq_chips do not have a disable hook so the __disable_irq() here is a NOP. Kevin _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
