On 8/25/21 8:42 PM, Vincent Whitchurch 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@xxxxxxxx>
Reviewed-by: Jaehoon Chung <jh80.chung@xxxxxxxxxxx>
Best Regards,
Jaehoon Chung
> ---
> 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) {
>
