diff mbox series

mmc: dw_mmc: Only inject fault before done/error

Message ID 20210825114213.7429-1-vincent.whitchurch@axis.com
State New
Headers show
Series mmc: dw_mmc: Only inject fault before done/error | expand

Commit Message

Vincent Whitchurch Aug. 25, 2021, 11:42 a.m. UTC
The fault injection function can set EVENT_DATA_ERROR but skip the
setting of ->data_status to an error status if it hits just after a data
over interrupt.  This confuses the tasklet which can later end up
triggering the WARN_ON(host->cmd || ..) in dw_mci_request_end() since
dw_mci_data_complete() would return success.

Prevent the fault injection function from doing this since this is not a
real case, and ensure that the fault injection doesn't race with a real
error either.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
---
 drivers/mmc/host/dw_mmc.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

Comments

Ulf Hansson Sept. 6, 2021, 5:09 p.m. UTC | #1
On Wed, 25 Aug 2021 at 13:42, Vincent Whitchurch
<vincent.whitchurch@axis.com> wrote:
>

> The fault injection function can set EVENT_DATA_ERROR but skip the

> setting of ->data_status to an error status if it hits just after a data

> over interrupt.  This confuses the tasklet which can later end up

> triggering the WARN_ON(host->cmd || ..) in dw_mci_request_end() since

> dw_mci_data_complete() would return success.

>

> Prevent the fault injection function from doing this since this is not a

> real case, and ensure that the fault injection doesn't race with a real

> error either.

>

> Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>


Applied for fixes and by adding a fixes tag, thanks!

Kind regards
Uffe


> ---

>  drivers/mmc/host/dw_mmc.c | 15 ++++++++++++---

>  1 file changed, 12 insertions(+), 3 deletions(-)

>

> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c

> index 6578cc64ae9e..380f9aa56eb2 100644

> --- a/drivers/mmc/host/dw_mmc.c

> +++ b/drivers/mmc/host/dw_mmc.c

> @@ -1802,10 +1802,15 @@ static enum hrtimer_restart dw_mci_fault_timer(struct hrtimer *t)

>

>         spin_lock_irqsave(&host->irq_lock, flags);

>

> -       if (!host->data_status)

> +       /*

> +        * Only inject an error if we haven't already got an error or data over

> +        * interrupt.

> +        */

> +       if (!host->data_status) {

>                 host->data_status = SDMMC_INT_DCRC;

> -       set_bit(EVENT_DATA_ERROR, &host->pending_events);

> -       tasklet_schedule(&host->tasklet);

> +               set_bit(EVENT_DATA_ERROR, &host->pending_events);

> +               tasklet_schedule(&host->tasklet);

> +       }

>

>         spin_unlock_irqrestore(&host->irq_lock, flags);

>

> @@ -2721,12 +2726,16 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)

>                 }

>

>                 if (pending & DW_MCI_DATA_ERROR_FLAGS) {

> +                       spin_lock(&host->irq_lock);

> +

>                         /* if there is an error report DATA_ERROR */

>                         mci_writel(host, RINTSTS, DW_MCI_DATA_ERROR_FLAGS);

>                         host->data_status = pending;

>                         smp_wmb(); /* drain writebuffer */

>                         set_bit(EVENT_DATA_ERROR, &host->pending_events);

>                         tasklet_schedule(&host->tasklet);

> +

> +                       spin_unlock(&host->irq_lock);

>                 }

>

>                 if (pending & SDMMC_INT_DATA_OVER) {

> --

> 2.28.0

>
diff mbox series

Patch

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 6578cc64ae9e..380f9aa56eb2 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1802,10 +1802,15 @@  static enum hrtimer_restart dw_mci_fault_timer(struct hrtimer *t)
 
 	spin_lock_irqsave(&host->irq_lock, flags);
 
-	if (!host->data_status)
+	/*
+	 * Only inject an error if we haven't already got an error or data over
+	 * interrupt.
+	 */
+	if (!host->data_status) {
 		host->data_status = SDMMC_INT_DCRC;
-	set_bit(EVENT_DATA_ERROR, &host->pending_events);
-	tasklet_schedule(&host->tasklet);
+		set_bit(EVENT_DATA_ERROR, &host->pending_events);
+		tasklet_schedule(&host->tasklet);
+	}
 
 	spin_unlock_irqrestore(&host->irq_lock, flags);
 
@@ -2721,12 +2726,16 @@  static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
 		}
 
 		if (pending & DW_MCI_DATA_ERROR_FLAGS) {
+			spin_lock(&host->irq_lock);
+
 			/* if there is an error report DATA_ERROR */
 			mci_writel(host, RINTSTS, DW_MCI_DATA_ERROR_FLAGS);
 			host->data_status = pending;
 			smp_wmb(); /* drain writebuffer */
 			set_bit(EVENT_DATA_ERROR, &host->pending_events);
 			tasklet_schedule(&host->tasklet);
+
+			spin_unlock(&host->irq_lock);
 		}
 
 		if (pending & SDMMC_INT_DATA_OVER) {