Skip to content

Commit

Permalink
fbdev: fix fillrect for 24bpp modes
Browse files Browse the repository at this point in the history 
The software fillrect routines do not work properly when the number of
pixels per machine word is not an integer.  To see that, run the following
command on a fbdev console with a 24bpp video mode, using a
non-accelerated driver such as (u)vesafb:

  reset ; echo -e '\e[41mtest\e[K'

The expected result is 'test' displayed on a line with red background.
Instead of that, 'test' has a red background, but the rest of the line
(rendered using fillrect()) contains a distored colorful pattern.

This patch fixes the problem by correctly computing rotation shifts.  It
has been tested in a 24bpp mode on 32- and 64-bit little-endian machines.

Signed-off-by: Michal Januszewski <spock@gentoo.org>
Acked-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  • Loading branch information
Michal Januszewski authored and Linus Torvalds committed May 6, 2009
1 parent 184101b commit bdca0f9
Show file tree
Hide file tree
Showing 3 changed files with 48 additions and 39 deletions.
36 changes: 16 additions & 20 deletions drivers/video/cfbfillrect.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -9,10 +9,6 @@
*
* NOTES:
*
* The code for depths like 24 that don't have integer number of pixels per
* long is broken and needs to be fixed. For now I turned these types of
* mode off.
*
* Also need to add code to deal with cards endians that are different than
* the native cpu endians. I also need to deal with MSB position in the word.
*
Expand Down Expand Up @@ -139,7 +135,7 @@ bitfill_unaligned(struct fb_info *p, unsigned long __iomem *dst, int dst_idx,

// Trailing bits
if (last)
FB_WRITEL(comp(pat, FB_READL(dst), first), dst);
FB_WRITEL(comp(pat, FB_READL(dst), last), dst);
}
}

Expand Down Expand Up @@ -281,7 +277,7 @@ bitfill_unaligned_rev(struct fb_info *p, unsigned long __iomem *dst,

void cfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
{
unsigned long pat, fg;
unsigned long pat, pat2, fg;
unsigned long width = rect->width, height = rect->height;
int bits = BITS_PER_LONG, bytes = bits >> 3;
u32 bpp = p->var.bits_per_pixel;
Expand All @@ -297,7 +293,7 @@ void cfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
else
fg = rect->color;

pat = pixel_to_pat( bpp, fg);
pat = pixel_to_pat(bpp, fg);

dst = (unsigned long __iomem *)((unsigned long)p->screen_base & ~(bytes-1));
dst_idx = ((unsigned long)p->screen_base & (bytes - 1))*8;
Expand Down Expand Up @@ -333,17 +329,16 @@ void cfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
dst_idx += p->fix.line_length*8;
}
} else {
int right;
int r;
int rot = (left-dst_idx) % bpp;
int right, r;
void (*fill_op)(struct fb_info *p, unsigned long __iomem *dst,
int dst_idx, unsigned long pat, int left,
int right, unsigned n, int bits) = NULL;

/* rotate pattern to correct start position */
pat = pat << rot | pat >> (bpp-rot);

right = bpp-left;
#ifdef __LITTLE_ENDIAN
right = left;
left = bpp - right;
#else
right = bpp - left;
#endif
switch (rect->rop) {
case ROP_XOR:
fill_op = bitfill_unaligned_rev;
Expand All @@ -352,17 +347,18 @@ void cfb_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
fill_op = bitfill_unaligned;
break;
default:
printk( KERN_ERR "cfb_fillrect(): unknown rop, defaulting to ROP_COPY\n");
printk(KERN_ERR "cfb_fillrect(): unknown rop, defaulting to ROP_COPY\n");
fill_op = bitfill_unaligned;
break;
}
while (height--) {
dst += dst_idx >> (ffs(bits) - 1);
dst += dst_idx / bits;
dst_idx &= (bits - 1);
fill_op(p, dst, dst_idx, pat, left, right,
r = dst_idx % bpp;
/* rotate pattern to the correct start position */
pat2 = le_long_to_cpu(rolx(cpu_to_le_long(pat), r, bpp));
fill_op(p, dst, dst_idx, pat2, left, right,
width*bpp, bits);
r = (p->fix.line_length*8) % bpp;
pat = pat << (bpp-r) | pat >> r;
dst_idx += p->fix.line_length*8;
}
}
Expand Down
21 changes: 17 additions & 4 deletions drivers/video/fb_draw.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -33,11 +33,11 @@ pixel_to_pat( u32 bpp, u32 pixel)
case 8:
return 0x0101010101010101ul*pixel;
case 12:
return 0x0001001001001001ul*pixel;
return 0x1001001001001001ul*pixel;
case 16:
return 0x0001000100010001ul*pixel;
case 24:
return 0x0000000001000001ul*pixel;
return 0x0001000001000001ul*pixel;
case 32:
return 0x0000000100000001ul*pixel;
default:
Expand All @@ -58,11 +58,11 @@ pixel_to_pat( u32 bpp, u32 pixel)
case 8:
return 0x01010101ul*pixel;
case 12:
return 0x00001001ul*pixel;
return 0x01001001ul*pixel;
case 16:
return 0x00010001ul*pixel;
case 24:
return 0x00000001ul*pixel;
return 0x01000001ul*pixel;
case 32:
return 0x00000001ul*pixel;
default:
Expand Down Expand Up @@ -167,4 +167,17 @@ static inline unsigned long fb_rev_pixels_in_long(unsigned long val,

#endif /* CONFIG_FB_CFB_REV_PIXELS_IN_BYTE */

#define cpu_to_le_long _cpu_to_le_long(BITS_PER_LONG)
#define _cpu_to_le_long(x) __cpu_to_le_long(x)
#define __cpu_to_le_long(x) cpu_to_le##x

#define le_long_to_cpu _le_long_to_cpu(BITS_PER_LONG)
#define _le_long_to_cpu(x) __le_long_to_cpu(x)
#define __le_long_to_cpu(x) le##x##_to_cpu

static inline unsigned long rolx(unsigned long word, unsigned int shift, unsigned int x)
{
return (word << shift) | (word >> (x - shift));
}

#endif /* FB_DRAW_H */
30 changes: 15 additions & 15 deletions drivers/video/sysfillrect.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -124,7 +124,7 @@ bitfill_unaligned(struct fb_info *p, unsigned long *dst, int dst_idx,

/* Trailing bits */
if (last)
*dst = comp(pat, *dst, first);
*dst = comp(pat, *dst, last);
}
}

Expand Down Expand Up @@ -242,7 +242,7 @@ bitfill_unaligned_rev(struct fb_info *p, unsigned long *dst, int dst_idx,

void sys_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
{
unsigned long pat, fg;
unsigned long pat, pat2, fg;
unsigned long width = rect->width, height = rect->height;
int bits = BITS_PER_LONG, bytes = bits >> 3;
u32 bpp = p->var.bits_per_pixel;
Expand Down Expand Up @@ -292,17 +292,16 @@ void sys_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
dst_idx += p->fix.line_length*8;
}
} else {
int right;
int r;
int rot = (left-dst_idx) % bpp;
int right, r;
void (*fill_op)(struct fb_info *p, unsigned long *dst,
int dst_idx, unsigned long pat, int left,
int right, unsigned n, int bits) = NULL;

/* rotate pattern to correct start position */
pat = pat << rot | pat >> (bpp-rot);

right = bpp-left;
#ifdef __LITTLE_ENDIAN
right = left;
left = bpp - right;
#else
right = bpp - left;
#endif
switch (rect->rop) {
case ROP_XOR:
fill_op = bitfill_unaligned_rev;
Expand All @@ -311,18 +310,19 @@ void sys_fillrect(struct fb_info *p, const struct fb_fillrect *rect)
fill_op = bitfill_unaligned;
break;
default:
printk(KERN_ERR "cfb_fillrect(): unknown rop, "
printk(KERN_ERR "sys_fillrect(): unknown rop, "
"defaulting to ROP_COPY\n");
fill_op = bitfill_unaligned;
break;
}
while (height--) {
dst += dst_idx >> (ffs(bits) - 1);
dst += dst_idx / bits;
dst_idx &= (bits - 1);
fill_op(p, dst, dst_idx, pat, left, right,
r = dst_idx % bpp;
/* rotate pattern to the correct start position */
pat2 = le_long_to_cpu(rolx(cpu_to_le_long(pat), r, bpp));
fill_op(p, dst, dst_idx, pat2, left, right,
width*bpp, bits);
r = (p->fix.line_length*8) % bpp;
pat = pat << (bpp-r) | pat >> r;
dst_idx += p->fix.line_length*8;
}
}
Expand Down

0 comments on commit bdca0f9

Please sign in to comment.