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

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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>
This commit is contained in:
Antonino A. Daplas
2005-12-12 22:17:21 -08:00
committed by Linus Torvalds
parent 7275b4b6bc
commit be0d9b6c7a
4 changed files with 36 additions and 36 deletions
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12
include/linux/fb.h
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@@ -833,6 +833,18 @@ struct fb_info {
#define fb_writeq(b,addr) (*(volatile u64 *) (addr) = (b))
#define fb_memset memset
#endif
#if defined (__BIG_ENDIAN)
#define FB_LEFT_POS(bpp) (32 - bpp)
#define FB_SHIFT_HIGH(val, bits) ((val) >> (bits))
#define FB_SHIFT_LOW(val, bits) ((val) << (bits))
#define FB_BIT_NR(b) (7 - (b))
#else
#define FB_LEFT_POS(bpp) (0)
#define FB_SHIFT_HIGH(val, bits) ((val) << (bits))
#define FB_SHIFT_LOW(val, bits) ((val) >> (bits))
#define FB_BIT_NR(b) (b)
#endif
/*