2013-05-10 10:21:44

by Andreas Fenkart

Subject: [PATCH 1/1] genirq: outline lazy disable in kerneldoc of irq_disable function.

comment based on changelog of d209a699a0b975ad

Signed-off-by: Andreas Fenkart <[email protected]>
---
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

2013-05-10 18:11:29

by Randy Dunlap

Subject: Re: [PATCH 1/1] genirq: outline lazy disable in kerneldoc of irq_disable function.

On 05/10/13 03:21, Andreas Fenkart wrote:
> comment based on changelog of d209a699a0b975ad
>
> Signed-off-by: Andreas Fenkart <[email protected]>
> ---
> 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

- mark interrupt 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);
>


--
~Randy

2013-05-29 09:25:16

by tip-bot for Vasyl Gomonovych

Subject: [tip:irq/core] genirq: Add kerneldoc for irq_disable.

Commit-ID: d671a605580d2caafc77f1a25bcf8435795df6fe
Gitweb: http://git.kernel.org/tip/d671a605580d2caafc77f1a25bcf8435795df6fe
Author: Andreas Fenkart <[email protected]>
AuthorDate: Fri, 10 May 2013 12:21:30 +0200
Committer: Thomas Gleixner <[email protected]>
CommitDate: Wed, 29 May 2013 11:09:10 +0200

genirq: Add kerneldoc for irq_disable.

Document the lazy disable functionality. comment based on changelog of
d209a699a0b975ad

Signed-off-by: Andreas Fenkart <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/1368181290-1583-1-git-send-email-andreas.fenkart@streamunlimited.com
Signed-off-by: Thomas Gleixner <[email protected]>
---
kernel/irq/chip.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index cbd97ce..a3bb14f 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);