2008-03-21 22:47:38

by Chris Wright

[permalink] [raw]
Subject: [patch 20/76] drivers: fix dma_get_required_mask

-stable review patch. If anyone has any objections, please let us know.
---------------------

From: James Bottomley <[email protected]>

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 <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Chris Wright <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/base/platform.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -647,7 +647,7 @@ u64 dma_get_required_mask(struct device
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

--