sdio: adaptive interrupt polling (6f4285d1) · Commits · 戴 / test

drivers/mmc/core/sdio_irq.c

+23 −5

Original line number	Diff line number	Diff line
		@@ -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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