[PATCH] fbcon: Console Rotation - Fix wrong shift calculation
The shift value (amount to shift the bitmap so first pixel starts at
origin(0,0)) is incorrect. This causes corrupted characters or a kernel crash
if fontwidth is not divisible by 8 at 270 degrees, or fontheight not divisible
by 8 at 180 degrees.
Report and part of the fix contributed by Knut Petersen.
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/video/console/fbcon_rotate.h b/drivers/video/console/fbcon_rotate.h
index 90c6720..e504fbf 100644
--- a/drivers/video/console/fbcon_rotate.h
+++ b/drivers/video/console/fbcon_rotate.h
@@ -49,7 +49,7 @@
static inline void rotate_ud(const char *in, char *out, u32 width, u32 height)
{
int i, j;
- int shift = width % 8;
+ int shift = (8 - (width % 8)) & 7;
width = (width + 7) & ~7;
@@ -85,7 +85,7 @@
static inline void rotate_ccw(const char *in, char *out, u32 width, u32 height)
{
int i, j, h = height, w = width;
- int shift = width % 8;
+ int shift = (8 - (width % 8)) & 7;
width = (width + 7) & ~7;
height = (height + 7) & ~7;