From: Stefan Nilsson XK stefan.xk.nilsson@stericsson.com
If there is only 1 function interrupt 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 Reviewed-by: Nicolas Pitre nicolas.pitre@linaro.org --- drivers/mmc/core/sdio_irq.c | 33 ++++++++++++++++++++++++++++++++- include/linux/mmc/card.h | 1 + 2 files changed, 33 insertions(+), 1 deletions(-)
diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c index b300161..03ead02 100644 --- a/drivers/mmc/core/sdio_irq.c +++ b/drivers/mmc/core/sdio_irq.c @@ -31,6 +31,17 @@ static int process_sdio_pending_irqs(struct mmc_card *card) { int i, ret, count; unsigned char pending; + struct sdio_func *func; + + /* + * Optimization, if there is only 1 function interrupt registered + * call irq handler directly + */ + func = card->sdio_single_irq; + if (func) { + func->irq_handler(func); + return 1; + }
ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending); if (ret) { @@ -42,7 +53,7 @@ static int process_sdio_pending_irqs(struct mmc_card *card) count = 0; for (i = 1; i <= 7; i++) { if (pending & (1 << i)) { - struct sdio_func *func = card->sdio_func[i - 1]; + func = card->sdio_func[i - 1]; if (!func) { printk(KERN_WARNING "%s: pending IRQ for " "non-existent function\n", @@ -186,6 +197,24 @@ 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 +256,7 @@ 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 +281,7 @@ 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, ®); diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h index d8dffc9..4910dec 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -191,6 +191,7 @@ 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 */