ps2: fix mouse stream corruption

Commit 7abe7eb294 "ps2: Fix mouse stream corruption due to lost data"
added code to avoid mouse stream corruptions but the calculation of
the needed free queue size was wrong. Fix this.

To reproduce, open a text file with the vim 7.3 32 bit for DOS exe-
cutable in a FreeDOS client started with -display sdl and move the
mouse around for a few seconds. You will quickly see erratic mouse
movements and unexpected mouse clicks. CuteMouse (ctmouse.exe) in
FreeDOS doesn't try to re-sync the mouse stream.

Fixes: 7abe7eb294 ("ps2: Fix mouse stream corruption due to lost data")
Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Message-Id: <20210525181441.27768-1-vr_qemu@t-online.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Volker Rümelin 2021-05-25 20:14:30 +02:00 committed by Gerd Hoffmann
parent 644f66bf5d
commit 76968101f5

View File

@ -646,7 +646,8 @@ void ps2_keyboard_set_translation(void *opaque, int mode)
static int ps2_mouse_send_packet(PS2MouseState *s)
{
const int needed = 3 + (s->mouse_type - 2);
/* IMPS/2 and IMEX send 4 bytes, PS2 sends 3 bytes */
const int needed = s->mouse_type ? 4 : 3;
unsigned int b;
int dx1, dy1, dz1;