Merge tag 'asoc-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound...

[cascardo/linux.git] / drivers / mmc / host / dw_mmc.c

diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 1ca5e72..72dc3cd 100644 (file)
--- 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 */