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authorAndreas Fenkart <andreas.fenkart@streamunlimited.com>2013-05-10 12:21:30 +0200
committerThomas Gleixner <tglx@linutronix.de>2013-05-29 11:09:10 +0200
commitd671a605580d2caafc77f1a25bcf8435795df6fe (patch)
treecad94ffca5b44af28fe51afcabd09cc87b0b0020 /kernel/irq
parente8bd834f73714378ef110a64287db1b77033c8da (diff)
downloadlinux-linaro-stable-d671a605580d2caafc77f1a25bcf8435795df6fe.tar.gz
genirq: Add kerneldoc for irq_disable.
Document the lazy disable functionality. comment based on changelog of d209a699a0b975ad Signed-off-by: Andreas Fenkart <andreas.fenkart@streamunlimited.com> 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 <tglx@linutronix.de>
Diffstat (limited to 'kernel/irq')
-rw-r--r--kernel/irq/chip.c13
1 files changed, 13 insertions, 0 deletions
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);