From be0d9b6c7aeaad1683059c00131cabd4c894c17c Mon Sep 17 00:00:00 2001 From: "Antonino A. Daplas" Date: Mon, 12 Dec 2005 22:17:21 -0800 Subject: [PATCH] fbdev: Fix incorrect unaligned access in little-endian machines The drawing function cfbfillrect does not work correctly when access is not unsigned-long aligned. It manifests as extra lines of pixels that are not complete drawn. Reversing the shift operator solves the problem, so I would presume that this bug would manifest only on little endian machines. The function cfbcopyarea may also have this bug. Aligned access should present no problems. Signed-off-by: Antonino Daplas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/video/cfbcopyarea.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/video/cfbcopyarea.c') diff --git a/drivers/video/cfbcopyarea.c b/drivers/video/cfbcopyarea.c index cdc71572cf35..74415325b016 100644 --- a/drivers/video/cfbcopyarea.c +++ b/drivers/video/cfbcopyarea.c @@ -64,8 +64,8 @@ bitcpy(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem *src int const shift = dst_idx-src_idx; int left, right; - first = ~0UL >> dst_idx; - last = ~(~0UL >> ((dst_idx+n) % bits)); + first = FB_SHIFT_HIGH(~0UL, dst_idx); + last = ~(FB_SHIFT_HIGH(~0UL, (dst_idx+n) % bits)); if (!shift) { // Same alignment for source and dest @@ -216,8 +216,8 @@ bitcpy_rev(unsigned long __iomem *dst, int dst_idx, const unsigned long __iomem shift = dst_idx-src_idx; - first = ~0UL << (bits - 1 - dst_idx); - last = ~(~0UL << (bits - 1 - ((dst_idx-n) % bits))); + first = FB_SHIFT_LOW(~0UL, bits - 1 - dst_idx); + last = ~(FB_SHIFT_LOW(~0UL, bits - 1 - ((dst_idx-n) % bits))); if (!shift) { // Same alignment for source and dest -- cgit v1.2.3