Commit 5c935165 authored by Doug Anderson's avatar Doug Anderson Committed by Ulf Hansson
Browse files

mmc: dw_mmc: Add a timeout for sending CMD11 



In the Designware databook's description of the "Voltage Switch Normal
Scenario" it instructs us to set a timer and fail the voltage change
if we don't see the voltage change interrupt within 2ms.  Let's
implement that.  Without implementing this I have often been able to
reproduce a hang while trying to send CMD11 on an rk3288-based board
while constantly ejecting and inserting UHS cards.

Signed-off-by: default avatarDoug Anderson <dianders@chromium.org>
Signed-off-by: default avatarJaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 488b8d63

drivers/mmc/host/dw_mmc.c

+26 −0
Original line number Diff line number Diff line
@@ -1021,6 +1021,15 @@ static void __dw_mci_start_request(struct dw_mci *host, 


	dw_mci_start_command(host, cmd, cmdflags);



	if (cmd->opcode == SD_SWITCH_VOLTAGE) {

		/*

		 * Databook says to fail after 2ms w/ no response; give an

		 * extra jiffy just in case we're about to roll over.

		 */

		mod_timer(&host->cmd11_timer,

			  jiffies + msecs_to_jiffies(2) + 1);

	}



	if (mrq->stop)

		host->stop_cmdr = dw_mci_prepare_command(slot->mmc, mrq->stop);

	else
@@ -2159,6 +2168,8 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id) 
		/* Check volt switch first, since it can look like an error */

		if ((host->state == STATE_SENDING_CMD11) &&

		    (pending & SDMMC_INT_VOLT_SWITCH)) {

			del_timer(&host->cmd11_timer);



			mci_writel(host, RINTSTS, SDMMC_INT_VOLT_SWITCH);

			pending &= ~SDMMC_INT_VOLT_SWITCH;

			dw_mci_cmd_interrupt(host, pending);
@@ -2572,6 +2583,18 @@ ciu_out: 
	return ret;

}



static void dw_mci_cmd11_timer(unsigned long arg)

{

	struct dw_mci *host = (struct dw_mci *)arg;



	if (host->state != STATE_SENDING_CMD11)

		dev_info(host->dev, "Unexpected CMD11 timeout\n");



	host->cmd_status = SDMMC_INT_RTO;

	set_bit(EVENT_CMD_COMPLETE, &host->pending_events);

	tasklet_schedule(&host->tasklet);

}



#ifdef CONFIG_OF

static struct dw_mci_of_quirks {

	char *quirk;
@@ -2746,6 +2769,9 @@ int dw_mci_probe(struct dw_mci *host) 
		}

	}



	setup_timer(&host->cmd11_timer,

		    dw_mci_cmd11_timer, (unsigned long)host);



	host->quirks = host->pdata->quirks;



	spin_lock_init(&host->lock);

include/linux/mmc/dw_mmc.h

+2 −0
Original line number Diff line number Diff line
@@ -202,6 +202,8 @@ struct dw_mci { 
	int			irq;



	int			sdio_id0;



	struct timer_list       cmd11_timer;

};



/* DMA ops for Internal/External DMAC interface */

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