* Jon Masters <jcm@xxxxxxxxxx> wrote: > On Mon, 2009-01-12 at 15:36 -0800, Eric W. Biederman wrote: > > > This hardware behavior is not specific to boot interrupts or Intel. > > It's not specific to Intel, but it is a specific compatibility behavior. > > > Is this case really so interesting and compelling that we want to > > fight through and figure what we need to do to make this work reliably > > on every x86 chipset? > > How else do you propose implementing IRQ handling in e.g. the RT kernel? > We get a hardware interrupt, we can't FastEOI, we can't process > synchronously, we can't do all of those things you might expect. > Implementing RT requires that we delay handling of the IRQ until > arbitrarily later in the future when we get around to it. a number of mainline drivers also mask/unmask irqs from within the IRQ handler. It's not particularly smart in a native driver, but can happen - and if we get an active line after that point (and this can happen because the driver is active), we are in trouble. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
