---

yaml
---
r: 312807
b: refs/heads/master
c: 94c6cee
h: refs/heads/master
i:
  312805: 782b587
  312803: 363c6c4
  312799: 79a3814
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b650352dd3df36164e3427bff3f33bc06ac47642
+refs/heads/master: 94c6cee91bebfc17596243b6a5f4fe910feec426

trunk/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)