IB/ipath: set up 32-bit DMA mask if 64-bit setup fails

Some systems do not set up 64-bit maps on systems with 2GB or less of
memory installed, so we have to fall back to trying a 32-bit setup.

Signed-off-by: Bryan O'Sullivan <bos@pathscale.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 13 insertions, 3 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_driver.c b/drivers/infiniband/hw/ipath/ipath_driver.c
index e7617c3982ea..7ff95b72d1fc 100644
--- a/drivers/infiniband/hw/ipath/ipath_driver.c
+++ b/drivers/infiniband/hw/ipath/ipath_driver.c
@@ -418,9 +418,19 @@ static int __devinit ipath_init_one(struct pci_dev *pdev,
 
         ret = pci_set_dma_mask(pdev, DMA_64BIT_MASK);
         if (ret) {
-                dev_info(&pdev->dev, "pci_set_dma_mask unit %u "
-                         "fails: %d\n", dd->ipath_unit, ret);
-                goto bail_regions;
+                /*
+                 * if the 64 bit setup fails, try 32 bit.  Some systems
+                 * do not setup 64 bit maps on systems with 2GB or less
+                 * memory installed.
+                 */
+                ret = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
+                if (ret) {
+                        dev_info(&pdev->dev, "pci_set_dma_mask unit %u "
+                                 "fails: %d\n", dd->ipath_unit, ret);
+                        goto bail_regions;
+                }
+                else
+                        ipath_dbg("No 64bit DMA mask, used 32 bit mask\n");
         }
 
         pci_set_master(pdev);