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: Doug Anderson <dianders@xxxxxxxxxxxx>
---
drivers/mmc/host/dw_mmc.c | 26 ++++++++++++++++++++++++++
include/linux/mmc/dw_mmc.h | 2 ++
2 files changed, 28 insertions(+)
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 47dfd0e..d259662 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1020,6 +1020,15 @@ 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
@@ -2158,6 +2167,8 @@ 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);
@@ -2571,6 +2582,18 @@ 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;
@@ -2745,6 +2768,9 @@ 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);
diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
index 471fb31..9efc567 100644
--- a/include/linux/mmc/dw_mmc.h
+++ b/include/linux/mmc/dw_mmc.h
@@ -202,6 +202,8 @@ struct dw_mci {
int irq;
int sdio_id0;
+
+ struct timer_list cmd11_timer;
};
/* DMA ops for Internal/External DMAC interface */
--
2.2.0.rc0.207.ga3a616c
--
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