Commit a536093a authored by Antonino A. Daplas's avatar Antonino A. Daplas Committed by Linus Torvalds

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

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: default avatarAntonino Daplas <adaplas@pol.net>
Acked-by: default avatarHerbert Poetzl <herbert@13thfloor.at>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 2cbbb3b5
...@@ -169,7 +169,7 @@ static inline void slow_imageblit(const struct fb_image *image, struct fb_info * ...@@ -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? */
......
...@@ -839,12 +839,10 @@ struct fb_info { ...@@ -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
/* /*
......
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