From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Mon, 10 Jun 2013 11:49:38 +0000 (+0100)
Subject: DMA-API: net: intel/ixgbevf: fix 32-bit DMA mask handling
X-Git-Tag: firefly_0821_release~176^2~4991^2~44
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=53567aa4e00399aa59339bba81b285a5b95f425c;p=firefly-linux-kernel-4.4.55.git

DMA-API: net: intel/ixgbevf: fix 32-bit DMA mask handling

The fallback to 32-bit DMA mask is rather odd:
	if (!dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)) &&
	    !dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64))) {
		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;
			}
		}
		pci_using_dac = 0;
	}
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@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---

diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index 59a62bbfb371..e34c2daac6a0 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -3326,19 +3326,14 @@ static int ixgbevf_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (err)
 		return err;
 
-	if (!dma_set_mask(&pdev->dev, DMA_BIT_MASK(64)) &&
-	    !dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(64))) {
+	if (!dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64))) {
 		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;
 		}
 		pci_using_dac = 0;
 	}