If the pixel size (bpp) is smaller than the word size (long) on a little
endian system, pixel data is written to the wrong part of the word.
Fix this by reversing the shifts on little endian systems.
Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
---
Seen on 16-bpp displays when drawing horizontal line segments that start
or end an odd pixel boundary.
---
drawops/bitstream.c | 28 ++++++++++++++++++----------
drawops/cfb.c | 25 +++++++++++++++++++------
include/types.h | 2 ++
3 files changed, 39 insertions(+), 16 deletions(-)
diff --git a/drawops/bitstream.c b/drawops/bitstream.c
index b3e09336cc477baa..06c74043b091846b 100644
--- a/drawops/bitstream.c
+++ b/drawops/bitstream.c
@@ -13,6 +13,14 @@
#include "bitstream.h"
#include "fb.h"
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+#define FIRST_MASK(idx) (~0UL << (idx))
+#define LAST_MASK(idx, n) (~(~0UL << (((idx)+(n)) % BITS_PER_LONG)))
+#else
+#define FIRST_MASK(idx) (~0UL >> (idx))
+#define LAST_MASK(idx, n) (~(~0UL >> (((idx)+(n)) % BITS_PER_LONG)))
+#endif
+
/*
* Compose two values, using a bitmask as decision value
@@ -42,8 +50,8 @@ void bitcpy(unsigned long *dst, int dst_idx, const unsigned long *src,
return;
shift = dst_idx-src_idx;
- first = ~0UL >> dst_idx;
- last = ~(~0UL >> ((dst_idx+n) % BITS_PER_LONG));
+ first = FIRST_MASK(dst_idx);
+ last = LAST_MASK(dst_idx, n);
if (!shift) {
// Same alignment for source and dest
@@ -190,8 +198,8 @@ void bitcpy_rev(unsigned long *dst, int dst_idx, const unsigned long *src,
}
shift = dst_idx-src_idx;
- first = ~0UL << (BITS_PER_LONG-1-dst_idx);
- last = ~(~0UL << (BITS_PER_LONG-1-((dst_idx-n) % BITS_PER_LONG)));
+ first = FIRST_MASK(BITS_PER_LONG-1-dst_idx);
+ last = LAST_MASK(BITS_PER_LONG-1-dst_idx, n);
if (!shift) {
// Same alignment for source and dest
@@ -328,8 +336,8 @@ void bitcpy_not(unsigned long *dst, int dst_idx, const unsigned long *src,
return;
shift = dst_idx-src_idx;
- first = ~0UL >> dst_idx;
- last = ~(~0UL >> ((dst_idx+n) % BITS_PER_LONG));
+ first = FIRST_MASK(dst_idx);
+ last = LAST_MASK(dst_idx, n);
if (!shift) {
// Same alignment for source and dest
@@ -465,8 +473,8 @@ void bitfill32(unsigned long *dst, int dst_idx, u32 pat, u32 n)
val |= val << 32;
#endif
- first = ~0UL >> dst_idx;
- last = ~(~0UL >> ((dst_idx+n) % BITS_PER_LONG));
+ first = FIRST_MASK(dst_idx);
+ last = LAST_MASK(dst_idx, n);
if (dst_idx+n <= BITS_PER_LONG) {
// Single word
@@ -520,8 +528,8 @@ void bitfill(unsigned long *dst, int dst_idx, unsigned long pat, int left,
if (!n)
return;
- first = ~0UL >> dst_idx;
- last = ~(~0UL >> ((dst_idx+n) % BITS_PER_LONG));
+ first = FIRST_MASK(dst_idx);
+ last = LAST_MASK(dst_idx, n);
if (dst_idx+n <= BITS_PER_LONG) {
// Single word
diff --git a/drawops/cfb.c b/drawops/cfb.c
index 1d8c88e7f23e983e..4a5a1ab654d75310 100644
--- a/drawops/cfb.c
+++ b/drawops/cfb.c
@@ -104,7 +104,7 @@ static inline unsigned long pixel_to_pat(pixel_t pixel, int left)
void cfb_draw_hline(u32 x, u32 y, u32 length, pixel_t pixel)
{
unsigned long *dst;
- int dst_idx, left;
+ int dst_idx, left, right;
u32 bpp = fb_var.bits_per_pixel;
dst = (unsigned long *)((unsigned long)fb & ~(BYTES_PER_LONG-1));
@@ -118,15 +118,22 @@ void cfb_draw_hline(u32 x, u32 y, u32 length, pixel_t pixel)
u32 pat = pixel_to_pat32(pixel);
bitfill32(dst, dst_idx, pat, length*bpp);
} else {
- unsigned long pat = pixel_to_pat(pixel, (left-dst_idx) % bpp);
- bitfill(dst, dst_idx, pat, left, bpp-left, length*bpp);
+ unsigned long pat;
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+ right = left;
+ left = bpp-left;
+#else
+ right = bpp-left;
+#endif
+ pat = pixel_to_pat(pixel, (left-dst_idx) % bpp);
+ bitfill(dst, dst_idx, pat, left, right, length*bpp);
}
}
void cfb_fill_rect(u32 x, u32 y, u32 width, u32 height, pixel_t pixel)
{
unsigned long *dst;
- int dst_idx, left;
+ int dst_idx, left, right;
u32 bpp = fb_var.bits_per_pixel;
dst = (unsigned long *)((unsigned long)fb & ~(BYTES_PER_LONG-1));
@@ -143,9 +150,15 @@ void cfb_fill_rect(u32 x, u32 y, u32 width, u32 height, pixel_t pixel)
dst_idx += next_line*8;
}
} else {
- unsigned long pat = pixel_to_pat(pixel, (left-dst_idx) % bpp);
- int right = bpp-left;
+ unsigned long pat;
int r;
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+ right = left;
+ left = bpp-left;
+#else
+ right = bpp-left;
+#endif
+ pat = pixel_to_pat(pixel, (left-dst_idx) % bpp);
while (height--) {
dst += dst_idx >> SHIFT_PER_LONG;
dst_idx &= (BITS_PER_LONG-1);
diff --git a/include/types.h b/include/types.h
index 8b11ee1b1b63ede6..33066fd299be79eb 100644
--- a/include/types.h
+++ b/include/types.h
@@ -9,6 +9,8 @@
* more details.
*/
+#include <endian.h>
+
/*
* Fixed size quantities
--
2.17.1
