Message-ID: <518D3828.9060000@infradead.org>
Date: Fri, 10 May 2013 11:10:48 -0700
From: Randy Dunlap <rdunlap@infradead.org>
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To: Andreas Fenkart <andreas.fenkart@streamunlimited.com>
CC: tglx@linutronix.de, linux-kernel@vger.kernel.org, balbi@ti.com
Subject: Re: [PATCH 1/1] genirq: outline lazy disable in kerneldoc of irq_disable
 function.
References: <1368181290-1583-1-git-send-email-andreas.fenkart@streamunlimited.com>
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On 05/10/13 03:21, Andreas Fenkart wrote:
> comment based on changelog of d209a699a0b975ad
> 
> Signed-off-by: Andreas Fenkart <andreas.fenkart@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

                  - 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
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