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[PATCH] fbcon: Fix big-endian bogosity in slow_imageblit()

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The monochrome->color expansion routine that handles bitmaps which have
(widths % 8) != 0 (slow_imageblit) produces corrupt characters in big-endian.
This is caused by a bogus bit test in slow_imageblit().

Fix.

This patch may deserve to go to the stable tree.  The code has already been
well tested in little-endian machines.  It's only in big-endian where there is
uncertainty and Herbert confirmed that this is the correct way to go.

It should not introduce regressions.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Acked-by: Herbert Poetzl <herbert@13thfloor.at>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Antonino A. Daplas
2006-03-31 02:31:54 -08:00
committed by Linus Torvalds
parent 2cbbb3b59c
commit a536093a2f
2 changed files with 1 additions and 3 deletions
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2
drivers/video/cfbimgblt.c
View File

@@ -169,7 +169,7 @@ static inline void slow_imageblit(const struct fb_image *image, struct fb_info *
while (j--) { while (j--) {
l--; l--;
color = (*s & 1 << (FB_BIT_NR(l))) ? fgcolor : bgcolor; color = (*s & (1 << l)) ? fgcolor : bgcolor;
val |= FB_SHIFT_HIGH(color, shift); val |= FB_SHIFT_HIGH(color, shift);
/* Did the bitshift spill bits to the next long? */ /* Did the bitshift spill bits to the next long? */

2
include/linux/fb.h
View File

@@ -839,12 +839,10 @@ struct fb_info {
#define FB_LEFT_POS(bpp) (32 - bpp) #define FB_LEFT_POS(bpp) (32 - bpp)
#define FB_SHIFT_HIGH(val, bits) ((val) >> (bits)) #define FB_SHIFT_HIGH(val, bits) ((val) >> (bits))
#define FB_SHIFT_LOW(val, bits) ((val) << (bits)) #define FB_SHIFT_LOW(val, bits) ((val) << (bits))
#define FB_BIT_NR(b) (7 - (b))
#else #else
#define FB_LEFT_POS(bpp) (0) #define FB_LEFT_POS(bpp) (0)
#define FB_SHIFT_HIGH(val, bits) ((val) << (bits)) #define FB_SHIFT_HIGH(val, bits) ((val) << (bits))
#define FB_SHIFT_LOW(val, bits) ((val) >> (bits)) #define FB_SHIFT_LOW(val, bits) ((val) >> (bits))
#define FB_BIT_NR(b) (b)
#endif #endif
/* /*