[PATCH] fbdev: Fix incorrect unaligned access in little-endian machines

The drawing function cfbfillrect does not work correctly when access is not
unsigned-long aligned.  It manifests as extra lines of pixels that are not
complete drawn.  Reversing the shift operator solves the problem, so I would
presume that this bug would manifest only on little endian machines.  The
function cfbcopyarea may also have this bug.

Aligned access should present no problems.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 8 insertions, 8 deletions

diff --git a/drivers/video/cfbfillrect.c b/drivers/video/cfbfillrect.c
index 167d9314e6eb..e5ff62e9cfb8 100644
--- a/drivers/video/cfbfillrect.c
+++ b/drivers/video/cfbfillrect.c
@@ -110,8 +110,8 @@ bitfill_aligned(unsigned long __iomem *dst, int dst_idx, unsigned long pat, unsi
         if (!n)
                 return;
 
-        first = ~0UL >> dst_idx;
-        last = ~(~0UL >> ((dst_idx+n) % bits));
+        first = FB_SHIFT_HIGH(~0UL, dst_idx);
+        last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
 
         if (dst_idx+n <= bits) {
                 // Single word
@@ -167,8 +167,8 @@ bitfill_unaligned(unsigned long __iomem *dst, int dst_idx, unsigned long pat,
         if (!n)
                 return;
 
-        first = ~0UL >> dst_idx;
-        last = ~(~0UL >> ((dst_idx+n) % bits));
+        first = FB_SHIFT_HIGH(~0UL, dst_idx);
+        last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
 
         if (dst_idx+n <= bits) {
                 // Single word
@@ -221,8 +221,8 @@ bitfill_aligned_rev(unsigned long __iomem *dst, int dst_idx, unsigned long pat,
         if (!n)
                 return;
 
-        first = ~0UL >> dst_idx;
-        last = ~(~0UL >> ((dst_idx+n) % bits));
+        first = FB_SHIFT_HIGH(~0UL, dst_idx);
+        last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
 
         if (dst_idx+n <= bits) {
                 // Single word
@@ -290,8 +290,8 @@ bitfill_unaligned_rev(unsigned long __iomem *dst, int dst_idx, unsigned long pat
         if (!n)
                 return;
 
-        first = ~0UL >> dst_idx;
-        last = ~(~0UL >> ((dst_idx+n) % bits));
+        first = FB_SHIFT_HIGH(~0UL, dst_idx);
+        last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits));
 
         if (dst_idx+n <= bits) {
                 // Single word