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-rw-r--r--drivers/mmc/core/sdio_irq.c28
1 files changed, 23 insertions, 5 deletions
diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c
index 8843a4c..f78ffee 100644
--- a/drivers/mmc/core/sdio_irq.c
+++ b/drivers/mmc/core/sdio_irq.c
@@ -27,7 +27,7 @@
static int process_sdio_pending_irqs(struct mmc_card *card)
{
- int i, ret;
+ int i, ret, count;
unsigned char pending;
ret = mmc_io_rw_direct(card, 0, 0, SDIO_CCCR_INTx, 0, &pending);
@@ -37,6 +37,7 @@ static int process_sdio_pending_irqs(struct mmc_card *card)
return ret;
}
+ count = 0;
for (i = 1; i <= 7; i++) {
if (pending & (1 << i)) {
struct sdio_func *func = card->sdio_func[i - 1];
@@ -46,20 +47,21 @@ static int process_sdio_pending_irqs(struct mmc_card *card)
sdio_func_id(func));
} else if (func->irq_handler) {
func->irq_handler(func);
+ count++;
} else
printk(KERN_WARNING "%s: pending IRQ with no handler\n",
sdio_func_id(func));
}
}
- return 0;
+ return count;
}
static int sdio_irq_thread(void *_host)
{
struct mmc_host *host = _host;
struct sched_param param = { .sched_priority = 1 };
- unsigned long period;
+ unsigned long period, idle_period;
int ret;
sched_setscheduler(current, SCHED_FIFO, &param);
@@ -70,8 +72,9 @@ static int sdio_irq_thread(void *_host)
* asynchronous notification of pending SDIO card interrupts
* hence we poll for them in that case.
*/
+ idle_period = msecs_to_jiffies(10);
period = (host->caps & MMC_CAP_SDIO_IRQ) ?
- MAX_SCHEDULE_TIMEOUT : msecs_to_jiffies(10);
+ MAX_SCHEDULE_TIMEOUT : idle_period;
pr_debug("%s: IRQ thread started (poll period = %lu jiffies)\n",
mmc_hostname(host), period);
@@ -101,9 +104,24 @@ static int sdio_irq_thread(void *_host)
* errors. FIXME: determine if due to card removal and
* possibly exit this thread if so.
*/
- if (ret)
+ if (ret < 0)
ssleep(1);
+ /*
+ * Adaptive polling frequency based on the assumption
+ * that an interrupt will be closely followed by more.
+ * This has a substantial benefit for network devices.
+ */
+ if (!(host->caps & MMC_CAP_SDIO_IRQ)) {
+ if (ret > 0)
+ period /= 2;
+ else {
+ period++;
+ if (period > idle_period)
+ period = idle_period;
+ }
+ }
+
set_task_state(current, TASK_INTERRUPTIBLE);
if (host->caps & MMC_CAP_SDIO_IRQ)
host->ops->enable_sdio_irq(host, 1);
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