On 4 May 2011 19:34, Nicolas Pitre nicolas.pitre@linaro.org wrote:
On Wed, 4 May 2011, Per Forlin wrote:
From: Stefan Nilsson XK stefan.xk.nilsson@stericsson.com
If there is only 1 function registered it is possible to improve performance by directly calling the irq handler and avoiding the overhead of reading the CCCR registers.
Signed-off-by: Per Forlin per.forlin@linaro.org Acked-by: Ulf Hansson ulf.hansson@stericsson.com
drivers/mmc/core/sdio_irq.c | 30 ++++++++++++++++++++++++++++++ include/linux/mmc/card.h | 1 + 2 files changed, 31 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c index b300161..64c4409 100644 --- a/drivers/mmc/core/sdio_irq.c +++ b/drivers/mmc/core/sdio_irq.c @@ -32,6 +32,16 @@ static int process_sdio_pending_irqs(struct mmc_card *card) int i, ret, count; unsigned char pending;
- /*
- * Optimization, if there is only 1 function registered
- * call irq handler directly
- */
- if (card->sdio_single_irq && card->sdio_single_irq->irq_handler) {
- struct sdio_func *func = card->sdio_single_irq;
- func->irq_handler(func);
I think there is little point using a func variable here, especially since you already reference the handler pointer in the if() statement. Hence:
if (card->sdio_single_irq && card->sdio_single_irq->irq_handler) { card->sdio_single_irq->irq_handler(); return 1; }
What do you think about: + struct sdio_func *func = card->sdio_single_irq; + + /* + * Optimization, if there is only 1 function interrupt registered + * call irq handler directly + */ + if (func) { + func->irq_handler(func); + return 1; + }
- struct sdio_func *func = card->sdio_func[i - 1]; + func = card->sdio_func[i - 1];
@@ -186,6 +196,24 @@ static int sdio_card_irq_put(struct mmc_card *card) return 0; }
+/* If there is only 1 function registered set sdio_single_irq */ +static void sdio_single_irq_set(struct mmc_card *card) +{
The comment is slightly wrong. This should say "only 1 function interrupt registered..." Nothing prevents this from working with multiple functions if only one of them has claimed an interrupt.
Other than that:
Reviewed-by: Nicolas Pitre nicolas.pitre@linaro.org
Nicolas