1 files changed, 23 insertions, 5 deletions

diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c
index 8843a4c2fe91..f78ffeefed52 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);