ahci: use dma_set_mask_and_coherent

Use the dma_set_mask_and_coherent helper to set the DMA mask.  Rely
on the relatively recent change that setting a larger than required
mask will never fail to avoid the need for the boilerplate 32-bit
fallback code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index f7652ba..ad840f2 100644 (file)
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -901,40 +901,23 @@ static int ahci_pci_device_resume(struct device *dev)
 
 static int ahci_configure_dma_masks(struct pci_dev *pdev, int using_dac)
 {
+       const int dma_bits = using_dac ? 64 : 32;
        int rc;
 
        /*
         * If the device fixup already set the dma_mask to some non-standard
         * value, don't extend it here. This happens on STA2X11, for example.
+        *
+        * XXX: manipulating the DMA mask from platform code is completely
+        * bogus, platform code should use dev->bus_dma_mask instead..
         */
        if (pdev->dma_mask && pdev->dma_mask < DMA_BIT_MASK(32))
                return 0;
 
-       if (using_dac &&
-           !dma_set_mask(&pdev->dev, DMA_BIT_MASK(64))) {
-               rc = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64));
-               if (rc) {
-                       rc = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
-                       if (rc) {
-                               dev_err(&pdev->dev,
-                                       "64-bit DMA enable failed\n");
-                               return rc;
-                       }
-               }
-       } else {
-               rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
-               if (rc) {
-                       dev_err(&pdev->dev, "32-bit DMA enable failed\n");
-                       return rc;
-               }
-               rc = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
-               if (rc) {
-                       dev_err(&pdev->dev,
-                               "32-bit consistent DMA enable failed\n");
-                       return rc;
-               }
-       }
-       return 0;
+       rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(dma_bits));
+       if (rc)
+               dev_err(&pdev->dev, "DMA enable failed\n");
+       return rc;
 }
 
 static void ahci_pci_print_info(struct ata_host *host)