[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: 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>

drivers/video/cfbimgblt.c

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

include/linux/fb.h

@@ -839,12 +839,10 @@ struct fb_info {
 #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
 
     /*