[PATCH 1/3] mach64: fix display corruption on big endian machines
Mikulas Patocka
mpatocka at redhat.com
Sat Aug 25 19:51:00 UTC 2018
The code for manual bit triple is not endian-clean. It builds the variable
"hostdword" using byte accesses, therefore we must read the variable with
"le32_to_cpu".
The patch also enables (hardware or software) bit triple only if the image
is monochrome (image->depth). If we want to blit full-color image, we
shouldn't use the triple code.
Signed-off-by: Mikulas Patocka <mpatocka at redhat.com>
Cc: stable at vger.kernel.org
---
drivers/video/fbdev/aty/mach64_accel.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
Index: linux-stable/drivers/video/fbdev/aty/mach64_accel.c
===================================================================
--- linux-stable.orig/drivers/video/fbdev/aty/mach64_accel.c 2018-08-24 17:31:21.000000000 +0200
+++ linux-stable/drivers/video/fbdev/aty/mach64_accel.c 2018-08-24 19:12:40.000000000 +0200
@@ -345,7 +345,7 @@ void atyfb_imageblit(struct fb_info *inf
* since Rage 3D IIc we have DP_HOST_TRIPLE_EN bit
* this hwaccelerated triple has an issue with not aligned data
*/
- if (M64_HAS(HW_TRIPLE) && image->width % 8 == 0)
+ if (image->depth == 1 && M64_HAS(HW_TRIPLE) && image->width % 8 == 0)
pix_width |= DP_HOST_TRIPLE_EN;
}
@@ -382,7 +382,7 @@ void atyfb_imageblit(struct fb_info *inf
src_bytes = (((image->width * image->depth) + 7) / 8) * image->height;
/* manual triple each pixel */
- if (info->var.bits_per_pixel == 24 && !(pix_width & DP_HOST_TRIPLE_EN)) {
+ if (image->depth == 1 && info->var.bits_per_pixel == 24 && !(pix_width & DP_HOST_TRIPLE_EN)) {
int inbit, outbit, mult24, byte_id_in_dword, width;
u8 *pbitmapin = (u8*)image->data, *pbitmapout;
u32 hostdword;
@@ -415,7 +415,7 @@ void atyfb_imageblit(struct fb_info *inf
}
}
wait_for_fifo(1, par);
- aty_st_le32(HOST_DATA0, hostdword, par);
+ aty_st_le32(HOST_DATA0, le32_to_cpu(hostdword), par);
}
} else {
u32 *pbitmap, dwords = (src_bytes + 3) / 4;
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