comment based on changelog of d209a699a0b975ad
Signed-off-by: Andreas Fenkart <andreas.fenk...@streamunlimited.com>
---
kernel/irq/chip.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index cbd97ce..4e3c439 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 - mask 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);
--
1.7.10.4
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