On Tue, 14 Aug 2007 13:52:42 +1000 (EST) David Gibson <[EMAIL PROTECTED]> wrote:
> At present the driver for the UIC (the embedded interrupt controller > in 4xx chips) uses the handle_level_irq() flow handler. It turns out > this does not correctly handle level triggered interrupts on the UIC. > > Specifically, acknowledging an irq on the UIC (i.e. clearing the > relevant bit in UIC_SR) will have no effect for a level interrupt > which is still asserted by the external device, even if the irq is > already masked. Therefore, unlike handle_level_irq() we must ack the > interrupt after invoking the ISR (which should cause the device to > stop asserting the irq) instead of acking it when we mask it, before > the ISR. > > This patch implements this change, in a new handle_uic_irq(), a > customised irq flow handler for the UIC. For edge triggered > interrupts, handle_uic_irq() still uses the old flow - we must ack > edge triggered interrupt before the ISR not after, or we could miss a > second event which occurred between invoking the ISR and acking the > irq. > > Signed-off-by: David Gibson <[EMAIL PROTECTED]> Acked-by: Josh Boyer <[EMAIL PROTECTED]> josh _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
