From d671a605580d2caafc77f1a25bcf8435795df6fe Mon Sep 17 00:00:00 2001 From: Andreas Fenkart Date: Fri, 10 May 2013 12:21:30 +0200 Subject: genirq: Add kerneldoc for irq_disable. Document the lazy disable functionality. comment based on changelog of d209a699a0b975ad Signed-off-by: Andreas Fenkart Cc: balbi@ti.com Link: http://lkml.kernel.org/r/1368181290-1583-1-git-send-email-andreas.fenkart@streamunlimited.com Signed-off-by: Thomas Gleixner --- kernel/irq/chip.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'kernel/irq') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index cbd97ce0b000..a3bb14fbe5c6 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -213,6 +213,19 @@ void irq_enable(struct irq_desc *desc) irq_state_clr_masked(desc); } +/** + * irq_disable - Mark interupt disabled + * @desc: irq descriptor which should be disabled + * + * If the chip does not implement the irq_disable callback, we + * use a lazy disable approach. That means we mark the interrupt + * disabled, but leave the hardware unmasked. That's an + * optimization because we avoid the hardware access for the + * common case where no interrupt happens after we marked it + * disabled. If an interrupt happens, then the interrupt flow + * handler masks the line at the hardware level and marks it + * pending. + */ void irq_disable(struct irq_desc *desc) { irq_state_set_disabled(desc); -- cgit v1.2.3