Merge commit 'c039c332f23e794deb6d6f37b9f07ff3b27fb2cf' into md

Pull in pre-requisites for adding raid10 support to dm-raid.

1 files changed, 14 insertions, 3 deletions

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 1ca5e72ceb65..72dc3cde646d 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -405,11 +405,23 @@ static void dw_mci_idmac_start_dma(struct dw_mci *host, unsigned int sg_len)
 static int dw_mci_idmac_init(struct dw_mci *host)
 {
 	struct idmac_desc *p;
-	int i;
+	int i, dma_support;
 
 	/* Number of descriptors in the ring buffer */
 	host->ring_size = PAGE_SIZE / sizeof(struct idmac_desc);
 
+	/* Check if Hardware Configuration Register has support for DMA */
+	dma_support = (mci_readl(host, HCON) >> 16) & 0x3;
+
+	if (!dma_support || dma_support > 2) {
+		dev_err(&host->dev,
+			"Host Controller does not support IDMA Tx.\n");
+		host->dma_ops = NULL;
+		return -ENODEV;
+	}
+
+	dev_info(&host->dev, "Using internal DMA controller.\n");
+
 	/* Forward link the descriptor list */
 	for (i = 0, p = host->sg_cpu; i < host->ring_size - 1; i++, p++)
 		p->des3 = host->sg_dma + (sizeof(struct idmac_desc) * (i + 1));
@@ -1876,7 +1888,6 @@ static void dw_mci_init_dma(struct dw_mci *host)
 	/* Determine which DMA interface to use */
 #ifdef CONFIG_MMC_DW_IDMAC
 	host->dma_ops = &dw_mci_idmac_ops;
-	dev_info(&host->dev, "Using internal DMA controller.\n");
 #endif
 
 	if (!host->dma_ops)
@@ -2175,7 +2186,7 @@ int dw_mci_resume(struct dw_mci *host)
 		return ret;
 	}
 
-	if (host->dma_ops->init)
+	if (host->use_dma && host->dma_ops->init)
 		host->dma_ops->init(host);
 
 	/* Restore the old value at FIFOTH register */