From: Jaehoon Chung <jh80.chung@samsung.com>
Date: Wed, 18 Apr 2012 06:42:31 +0000 (+0900)
Subject: mmc: dw_mmc: prevent NULL dereference for dma_ops
X-Git-Tag: v3.4-rc4~3^2~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e1631f989e0c6c8d9b43a2dbdd1097f70da603a5;p=profile%2Fcommon%2Fkernel-common.git

mmc: dw_mmc: prevent NULL dereference for dma_ops

Now, dma_ops is assumed that use the IDMAC.  But if dma_ops is assigned
the pdata->dma_ops, we didn't ensure that callback function is defined.

If the callback isn't defined, then we should run in PIO mode.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
---

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index f3b0fcd..ab3fc46 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1881,7 +1881,8 @@ static void dw_mci_init_dma(struct dw_mci *host)
 	if (!host->dma_ops)
 		goto no_dma;
 
-	if (host->dma_ops->init) {
+	if (host->dma_ops->init && host->dma_ops->start &&
+	    host->dma_ops->stop && host->dma_ops->cleanup) {
 		if (host->dma_ops->init(host)) {
 			dev_err(&host->dev, "%s: Unable to initialize "
 				"DMA Controller.\n", __func__);