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

commit dc4ff9bb7534ebd153f8441ec0e9190964ad8944 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@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 76e43c417a3171b8b2019952dffec1f1e56ce9a1..318017d7dadac6daa2b2725b12a89452a2a24ac2 100644 (file)
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -2034,21 +2034,15 @@ static int igb_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;
                }
        }