fbdev: fix fillrect for 24bpp modes
authorMichal Januszewski <spock@gentoo.org>
Wed, 6 May 2009 23:02:56 +0000 (16:02 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 6 May 2009 23:36:10 +0000 (16:36 -0700)
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>
drivers/video/cfbfillrect.c
drivers/video/fb_draw.h
drivers/video/sysfillrect.c

index 64b35766b2a26bf28ccb1cfb55990c159008ca45..ba9f58b2a5e86e65a29aa3cabc67d45087b933b9 100644 (file)
@@ -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.
  *
@@ -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);
        }
 }
 
@@ -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;
@@ -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;
@@ -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;
@@ -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;
                }
        }
index 1db622192bde2252553eb91ce69123d6fc69512f..04c01faaf7721b71041461f56c6b2032d3085d81 100644 (file)
@@ -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:
@@ -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:
@@ -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 */
index f94d6b6e29eeb9f57c4082f6a09190ca055d3278..33ee3d34f9d24004c85002ff9be86cbc25d62eef 100644 (file)
@@ -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);
        }
 }
 
@@ -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;
@@ -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;
@@ -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;
                }
        }