[PATCH 2/2] mci: arasan: configure data transfer only if we actually have data

[Michael Tretter]

If we don't have any data to transfer, we must not set the block size
and block count.

If data is NULL, accessing data to get the block size and block count is
a NULL pointer dereference.

Signed-off-by: Michael Tretter <m.tretter at pengutronix.de>
---
 drivers/mci/arasan-sdhci.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/mci/arasan-sdhci.c b/drivers/mci/arasan-sdhci.c
index 399966e8cf10..3d738774e825 100644
--- a/drivers/mci/arasan-sdhci.c
+++ b/drivers/mci/arasan-sdhci.c
@@ -283,10 +283,12 @@ static int arasan_sdhci_send_cmd(struct mci_host *mci, struct mci_cmd *cmd,
 	sdhci_set_cmd_xfer_mode(&host->sdhci, cmd, data, false, &command, &xfer);
 
 	sdhci_write8(&host->sdhci, SDHCI_TIMEOUT_CONTROL, TIMEOUT_VAL);
-	sdhci_write16(&host->sdhci, SDHCI_TRANSFER_MODE, xfer);
-	sdhci_write16(&host->sdhci, SDHCI_BLOCK_SIZE, SDHCI_DMA_BOUNDARY_512K |
-			    SDHCI_TRANSFER_BLOCK_SIZE(data->blocksize));
-	sdhci_write16(&host->sdhci, SDHCI_BLOCK_COUNT, data->blocks);
+	if (data) {
+		sdhci_write16(&host->sdhci, SDHCI_TRANSFER_MODE, xfer);
+		sdhci_write16(&host->sdhci, SDHCI_BLOCK_SIZE,
+			      SDHCI_DMA_BOUNDARY_512K | SDHCI_TRANSFER_BLOCK_SIZE(data->blocksize));
+		sdhci_write16(&host->sdhci, SDHCI_BLOCK_COUNT, data->blocks);
+	}
 	sdhci_write32(&host->sdhci, SDHCI_ARGUMENT, cmd->cmdarg);
 	sdhci_write16(&host->sdhci, SDHCI_COMMAND, command);
 
-- 
2.29.2