On Fri, Aug 23, 2013 at 3:30 PM, Ingo Molnar <[email protected]> wrote: > > * Liu Ping Fan <[email protected]> wrote: > >> When programming ioapic pinX more than once, current code >> does not check whether the later attr (trigger&polarity) is the >> same as the former or not. This causes a broken semantic. >> >> Fix it by reporting -EBUSY, when attr is different. > > Was this observed in real life somehow, and if yes, what is > the before/after behavior? > Using qemu q35 machine, I found the ioapic's ioredtbl[] will never has low-active, even the hpet driver registered it. After tracing, I found it shared a high-level active IRQ line with other device. So in fact, the acpi_register_gsi(, ACPI_ACTIVE_LOW) in hpet driver fail, but it did not detect it. The effect in qemu: when hpet-dev assert low-level, the kernel can not respond.
Thanks, Pingfan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
