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| author | Antonino A. Daplas <adaplas@gmail.com> | 2005-12-12 22:17:21 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-12-12 22:31:17 -0800 |
| commit | be0d9b6c7aeaad1683059c00131cabd4c894c17c (patch) | |
| tree | f7e55af855531331113cbddb98688f3901d48425 /include/linux/fb.h | |
| parent | 7275b4b6bc2f783c135c3f0eeecc4fdc6e788aa8 (diff) | |
| download | lwn-be0d9b6c7aeaad1683059c00131cabd4c894c17c.tar.gz lwn-be0d9b6c7aeaad1683059c00131cabd4c894c17c.zip | |
[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>
Diffstat (limited to 'include/linux/fb.h')
| -rw-r--r-- | include/linux/fb.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/include/linux/fb.h b/include/linux/fb.h index dab3a4decb44..a973be2cfe61 100644 --- a/include/linux/fb.h +++ b/include/linux/fb.h @@ -835,6 +835,18 @@ struct fb_info { #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 + /* * `Generic' versions of the frame buffer device operations */ |