[PATCH 1/1] mmc: remove redundant irq disabling

[PATCH 1/1] mmc: remove redundant irq disabling

[John Ogness]

From: John Ogness <john.ogness@linutronix.de>

There is no need to disable irq's when using the sg_copy_*_buffer()
functions because those functions do that already. There are also
no races for the mm_queue struct here that would require the irq's
to be disabled before calling sg_copy_*_buffer().

Signed-off-by: John Ogness <john.ogness@linutronix.de>
---
Patch against linux-next-20110324.

 drivers/mmc/card/queue.c |    8 --------
 1 files changed, 0 insertions(+), 8 deletions(-)

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 2ae7275..c07322c 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -343,18 +343,14 @@ unsigned int mmc_queue_map_sg(struct mmc_queue *mq)
  */
 void mmc_queue_bounce_pre(struct mmc_queue *mq)
 {
-	unsigned long flags;
-
 	if (!mq->bounce_buf)
 		return;
 
 	if (rq_data_dir(mq->req) != WRITE)
 		return;
 
-	local_irq_save(flags);
 	sg_copy_to_buffer(mq->bounce_sg, mq->bounce_sg_len,
 		mq->bounce_buf, mq->sg[0].length);
-	local_irq_restore(flags);
 }
 
 /*
@@ -363,17 +359,13 @@ void mmc_queue_bounce_pre(struct mmc_queue *mq)
  */
 void mmc_queue_bounce_post(struct mmc_queue *mq)
 {
-	unsigned long flags;
-
 	if (!mq->bounce_buf)
 		return;
 
 	if (rq_data_dir(mq->req) != READ)
 		return;
 
-	local_irq_save(flags);
 	sg_copy_from_buffer(mq->bounce_sg, mq->bounce_sg_len,
 		mq->bounce_buf, mq->sg[0].length);
-	local_irq_restore(flags);
 }
 
-- 
1.7.2.5

Re: [PATCH 1/1] mmc: remove redundant irq disabling

[Chris Ball]

Hi John,

On Fri, Mar 25 2011, John Ogness wrote:
> From: John Ogness <john.ogness@linutronix.de>
>
> There is no need to disable irq's when using the sg_copy_*_buffer()
> functions because those functions do that already. There are also
> no races for the mm_queue struct here that would require the irq's
> to be disabled before calling sg_copy_*_buffer().
>
> Signed-off-by: John Ogness <john.ogness@linutronix.de>
> ---
> Patch against linux-next-20110324.
>
>  drivers/mmc/card/queue.c |    8 --------
>  1 files changed, 0 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
> index 2ae7275..c07322c 100644
> --- a/drivers/mmc/card/queue.c
> +++ b/drivers/mmc/card/queue.c
> @@ -343,18 +343,14 @@ unsigned int mmc_queue_map_sg(struct mmc_queue *mq)
>   */
>  void mmc_queue_bounce_pre(struct mmc_queue *mq)
>  {
> -	unsigned long flags;
> -
>  	if (!mq->bounce_buf)
>  		return;
>  
>  	if (rq_data_dir(mq->req) != WRITE)
>  		return;
>  
> -	local_irq_save(flags);
>  	sg_copy_to_buffer(mq->bounce_sg, mq->bounce_sg_len,
>  		mq->bounce_buf, mq->sg[0].length);
> -	local_irq_restore(flags);
>  }
>  
>  /*
> @@ -363,17 +359,13 @@ void mmc_queue_bounce_pre(struct mmc_queue *mq)
>   */
>  void mmc_queue_bounce_post(struct mmc_queue *mq)
>  {
> -	unsigned long flags;
> -
>  	if (!mq->bounce_buf)
>  		return;
>  
>  	if (rq_data_dir(mq->req) != READ)
>  		return;
>  
> -	local_irq_save(flags);
>  	sg_copy_from_buffer(mq->bounce_sg, mq->bounce_sg_len,
>  		mq->bounce_buf, mq->sg[0].length);
> -	local_irq_restore(flags);
>  }

Thanks, I'll push this to mmc-next for .40.

- Chris.
-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child