drivers: fix dma_get_required_mask

There's a bug in the current implementation of dma_get_required_mask()
where it ands the returned mask with the current device mask.  This
rather defeats the purpose if you're using the call to determine what
your mask should be (since you will at that time have the default
DMA_32BIT_MASK).  This bug results in any driver that uses this function
*always* getting a 32 bit mask, which is wrong.

Fix by removing the and with dev->dma_mask.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index efaf282c438c4108b1f01c41dc6b873c0fde669d..911ec600fe71dec287cf922441a8cf53855ecf3f 100644 (file)
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -648,7 +648,7 @@ u64 dma_get_required_mask(struct device *dev)
                high_totalram += high_totalram - 1;
                mask = (((u64)high_totalram) << 32) + 0xffffffff;
        }
-       return mask & *dev->dma_mask;
+       return mask;
 }
 EXPORT_SYMBOL_GPL(dma_get_required_mask);
 #endif