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mmc: sdio: optimized SDIO IRQ handling for single irq 

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>
Signed-off-by: Chris Ball <cjb@laptop.org>
hifive-unleashed-5.1
Stefan Nilsson XK 2011-05-11 17:48:05 +02:00 committed by Chris Ball
parent 253d6a280f
commit 06e8935feb
2 changed files with 33 additions and 1 deletions
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33
drivers/mmc/core/sdio_irq.c
View File

@ -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, &reg);

1
include/linux/mmc/card.h
View File

@ -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 */