From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Mon, 10 Jun 2013 11:46:11 +0000 (+0100)
Subject: DMA-API: net: intel/ixgb: fix 32-bit DMA mask handling
X-Git-Tag: next-20131017~104^2^4~46
X-Git-Url: https://git.kernelconcepts.de/?p=karo-tx-linux.git;a=commitdiff_plain;h=590990362b939bc6edf8e05bd0f3146b33a42870

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

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) {
				pr_err("No usable DMA configuration, aborting\n");
				goto err_dma_mask;
			}
		}
	}
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/ixgb/ixgb_main.c b/drivers/net/ethernet/intel/ixgb/ixgb_main.c
index 9f6b236828e6..57e390cbe6d0 100644
--- a/drivers/net/ethernet/intel/ixgb/ixgb_main.c
+++ b/drivers/net/ethernet/intel/ixgb/ixgb_main.c
@@ -408,20 +408,14 @@ ixgb_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) {
-				pr_err("No usable DMA configuration, aborting\n");
-				goto err_dma_mask;
-			}
+			pr_err("No usable DMA configuration, aborting\n");
+			goto err_dma_mask;
 		}
 	}