[PATCH 3.12 088/104] DMA-API: net: intel/igbvf: fix 32-bit DMA mask handling

[Jiri Slaby]

From: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit c21b8ebc2f1613fd0a9d5aa0d0d1083aee8ca306 upstream.

The fallback to 32-bit DMA mask is rather odd:
	err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
	if (!err) {
		err = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64));
		if (!err)
			pci_using_dac = 1;
	} else {
		err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
		if (err) {
			err = dma_set_coherent_mask(&pdev->dev,
						    DMA_BIT_MASK(32));
			if (err) {
				dev_err(&pdev->dev, "No usable DMA "
					"configuration, aborting\n");
				goto err_dma;
			}
		}
	}
This means we only set the coherent DMA mask in the fallback path if
the DMA mask set failed, which is silly.  This fixes it to set the
coherent DMA mask only if dma_set_mask() succeeded, and to error out
if either fails.

Acked-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 drivers/net/ethernet/intel/igbvf/netdev.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/intel/igbvf/netdev.c b/drivers/net/ethernet/intel/igbvf/netdev.c
index 93eb7ee06d3e..4e6b02fbe652 100644
--- a/drivers/net/ethernet/intel/igbvf/netdev.c
+++ b/drivers/net/ethernet/intel/igbvf/netdev.c
@@ -2638,21 +2638,15 @@ static int igbvf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		return err;
 
 	pci_using_dac = 0;
-	err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
+	err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
 	if (!err) {
-		err = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64));
-		if (!err)
-			pci_using_dac = 1;
+		pci_using_dac = 1;
 	} else {
-		err = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
+		err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 		if (err) {
-			err = dma_set_coherent_mask(&pdev->dev,
-						    DMA_BIT_MASK(32));
-			if (err) {
-				dev_err(&pdev->dev, "No usable DMA "
-				        "configuration, aborting\n");
-				goto err_dma;
-			}
+			dev_err(&pdev->dev, "No usable DMA "
+			        "configuration, aborting\n");
+			goto err_dma;
 		}
 	}
 
-- 
2.0.4

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