On Wed, May 20, 2015 at 11:16:53AM +0200, Hans de Goede wrote: > On v7 touchpads sometimes when 2 fingers are moved down on the touchpad > until they "fall of" the touchpad, the second touch will report 0 for y > (max y really since the y axis is inverted) and max x as coordinates, > rather then reporting 0, 0 as is expected for a non touching finger. > > This commit detects this and treats these touches as non touching. > > See the evemu-recording here: > https://bugzilla.redhat.com/attachment.cgi?id=1025058 > > BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1221200 > Signed-off-by: Hans de Goede <[email protected]> > --- > drivers/input/mouse/alps.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c > index 745921f..9bc4343 100644 > --- a/drivers/input/mouse/alps.c > +++ b/drivers/input/mouse/alps.c > @@ -949,6 +949,11 @@ static void alps_get_finger_coordinate_v7(struct > input_mt_pos *mt, > case V7_PACKET_ID_TWO: > mt[1].x &= ~0x000F; > mt[1].y |= 0x000F; > + /* Detect false-postive touches where x & y report max value */ > + if (mt[1].y == 0x7ff && mt[1].x == 0xff0) { > + mt[1].x = 0; > + /* y gets set to 0 at the end of this function */
I think this is too fragile; I believe we can spare an assignment and maybe compiler will optimize it out. I can fix it up locally unless there are objections to having this extra assignment. > + } > break; > > case V7_PACKET_ID_MULTI: > -- > 2.4.1 > Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
