[PATCH 1/2] ahci: Check and set 64-bit DMA mask for platform AHCI driver

[suravee.suthikulpanit]

From: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>

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@xxxxxxx>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
 drivers/ata/libahci_platform.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c
index 3a5b4ed..a958a2b 100644
--- a/drivers/ata/libahci_platform.c
+++ b/drivers/ata/libahci_platform.c
@@ -364,6 +364,19 @@ 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;
-- 
1.9.0

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