ahci: Check and set 64-bit DMA mask for platform AHCI driver

The current platform AHCI driver does not set the dma_mask correctly
for 64-bit DMA capable AHCI controller. This patch checks the AHCI
capability bit and set the dma_mask and coherent_dma_mask accordingly.

Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Suman Tripathi <stripathi@apm.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
(cherry picked from commit cc7a9e27562cd78a1dc885504086fab24addce40)

diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
index b0077589f065889318bf92c564786db1d8171c6e..28840a2f470f03fd1d0e34f0c43db42800d24ca9 100644 (file)
--- a/drivers/ata/libahci_platform.c
+++ b/drivers/ata/libahci_platform.c
@@ -369,6 +369,19 @@ int ahci_platform_init_host(struct platform_device *pdev,
                        ap->ops = &ata_dummy_port_ops;
        }
 
+       if (hpriv->cap & HOST_CAP_64) {
+               rc = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
+               if (rc) {
+                       rc = dma_coerce_mask_and_coherent(dev,
+                                                         DMA_BIT_MASK(32));
+                       if (rc) {
+                               dev_err(dev, "Failed to enable 64-bit DMA.\n");
+                               return rc;
+                       }
+                       dev_warn(dev, "Enable 32-bit DMA instead of 64-bit.\n");
+               }
+       }
+
        rc = ahci_reset_controller(host);
        if (rc)
                return rc;