mmc: dw_mmc: Don't crash if we get an interrupt before slot has initted

It's unlikely that this is really needed on any single-slot systems
where we disable card detects until the end of probe, but it still
seems safer to check to make sure that a slot has been initted before
we try to dereference it to find the SDIO interrupt mask.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Tested-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index a1c8f72..b46b825 100644 (file)
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -2217,6 +2217,10 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
                /* Handle SDIO Interrupts */
                for (i = 0; i < host->num_slots; i++) {
                        struct dw_mci_slot *slot = host->slot[i];
+
+                       if (!slot)
+                               continue;
+
                        if (pending & SDMMC_INT_SDIO(slot->sdio_id)) {
                                mci_writel(host, RINTSTS,
                                           SDMMC_INT_SDIO(slot->sdio_id));