mmc: atmel-mci: Check pdata for NULL before dereferencing it at DMA config

Using an at91sam9g20ek development board with DTS configuration may trigger
a kernel panic because of a NULL pointer dereference exception, while
configuring DMA. Let's fix this by adding a check for pdata before
dereferencing it.

Signed-off-by: Brent Taylor <motobud@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 7f9d3de9f8700b3f1ea3767c5115dff9b43fa54e..9268c41a8561c7fbfc56089d238a4756e2115218 100644 (file)
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -2438,7 +2438,7 @@ static int atmci_configure_dma(struct atmel_mci *host)
                struct mci_platform_data *pdata = host->pdev->dev.platform_data;
                dma_cap_mask_t mask;
 
-               if (!pdata->dma_filter)
+               if (!pdata || !pdata->dma_filter)
                        return -ENODEV;
 
                dma_cap_zero(mask);