From e1631f989e0c6c8d9b43a2dbdd1097f70da603a5 Mon Sep 17 00:00:00 2001 From: Jaehoon Chung Date: Wed, 18 Apr 2012 15:42:31 +0900 Subject: [PATCH] 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 Signed-off-by: Kyungmin Park Acked-by: Will Newton Signed-off-by: Chris Ball --- drivers/mmc/host/dw_mmc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index f3b0fcd002df..ab3fc4617107 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__); -- 2.20.1