lkml.org 
[lkml]   [2011]   [May]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v2] sdio: optimized SDIO IRQ handling for single irq
    Date
    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);
    + return 1;
    + }
    +
    ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
    if (ret) {
    printk(KERN_DEBUG "%s: error %d reading SDIO_CCCR_INTx\n",
    @@ -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)
    +{
    + struct sdio_func *func;
    + int i;
    +
    + card->sdio_single_irq = NULL;
    + if ((card->host->caps & MMC_CAP_SDIO_IRQ) &&
    + card->host->sdio_irqs == 1)
    + for (i = 0; i < card->sdio_funcs; i++) {
    + func = card->sdio_func[i];
    + if (func && func->irq_handler) {
    + card->sdio_single_irq = func;
    + break;
    + }
    + }
    +}
    +
    /**
    * sdio_claim_irq - claim the IRQ for a SDIO function
    * @func: SDIO function
    @@ -227,6 +255,7 @@ int sdio_claim_irq(struct sdio_func *func, sdio_irq_handler_t *handler)
    ret = sdio_card_irq_get(func->card);
    if (ret)
    func->irq_handler = NULL;
    + sdio_single_irq_set(func->card);

    return ret;
    }
    @@ -251,6 +280,7 @@ int sdio_release_irq(struct sdio_func *func)
    if (func->irq_handler) {
    func->irq_handler = NULL;
    sdio_card_irq_put(func->card);
    + sdio_single_irq_set(func->card);
    }

    ret = mmc_io_rw_direct(func->card, 0, 0, SDIO_CCCR_IENx, 0, &reg);
    diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
    index adb4888..0d64211 100644
    --- a/include/linux/mmc/card.h
    +++ b/include/linux/mmc/card.h
    @@ -145,6 +145,7 @@ struct mmc_card {
    struct sdio_cccr cccr; /* common card info */
    struct sdio_cis cis; /* common tuple info */
    struct sdio_func *sdio_func[SDIO_MAX_FUNCS]; /* SDIO functions (devices) */
    + struct sdio_func *sdio_single_irq; /* SDIO function when only one IRQ active */
    unsigned num_info; /* number of info strings */
    const char **info; /* info strings */
    struct sdio_func_tuple *tuples; /* unknown common tuples */
    --
    1.7.4.1


    \
     
     \ /
      Last update: 2011-05-04 18:09    [W:0.023 / U:59.268 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site