From 5d26f91c89757a8b84f5da9c6dfa37cda19283c5 Mon Sep 17 00:00:00 2001 From: Wolfgang Bumiller Date: Wed, 25 Jan 2017 14:48:57 +0100 Subject: [PATCH] cirrus: handle negative pitch in cirrus_invalidate_region() cirrus_invalidate_region() calls memory_region_set_dirty() on a per-line basis, always ranging from off_begin to off_begin+bytesperline. With a negative pitch off_begin marks the top most used address and thus we need to do an initial shift backwards by a line for negative pitches of backward blits, otherwise the first iteration covers the line going from the start offset forwards instead of backwards. Additionally since the start address is inclusive, if we shift by a full `bytesperline` we move to the first address *not* included in the blit, so we only shift by one less than bytesperline. Signed-off-by: Wolfgang Bumiller Message-id: 1485352137-29367-1-git-send-email-w.bumiller@proxmox.com [ kraxel: codestyle fixes ] Signed-off-by: Gerd Hoffmann (cherry picked from commit f153b563f8cf121aebf5a2fff5f0110faf58ccb3) Signed-off-by: Michael Roth --- hw/display/cirrus_vga.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c index 67663490cf7..52bd9ff60ae 100644 --- a/hw/display/cirrus_vga.c +++ b/hw/display/cirrus_vga.c @@ -660,9 +660,14 @@ static void cirrus_invalidate_region(CirrusVGAState * s, int off_begin, int off_cur; int off_cur_end; + if (off_pitch < 0) { + off_begin -= bytesperline - 1; + } + for (y = 0; y < lines; y++) { off_cur = off_begin; off_cur_end = (off_cur + bytesperline) & s->cirrus_addr_mask; + assert(off_cur_end >= off_cur); memory_region_set_dirty(&s->vga.vram, off_cur, off_cur_end - off_cur); off_begin += off_pitch; } -- 2.39.5