Re: [PATCH] HID: add multi-input quirk for NextWindow Touchscreen.

From: Peter Hutterer
Date: Thu Dec 03 2009 - 17:09:11 EST


On 03/12/09 22:15, Peter Korsgaard wrote:
"Peter" == Peter Hutterer<peter.hutterer@xxxxxxxxxx> writes:

Peter> These touchscreens are mounted onto HP TouchSmart and the Dell
Peter> Studio One 19. Without a quirk they report a wrong button set
Peter> and the x/y coordinates through ABS_Z/ABS_RX, confusing the
Peter> higher levels (most notably X.Org's evdev driver).

What exactly does this fix? I've been using NW touchscreens for a while
and don't recall any issues (admittedly only used it with evtouch).

evtouch has the following code:

if ( (ev->code == ABS_X) || (ev->code == ABS_Z) ) {
priv->raw_x = ev->value;
pos_changed = 1;
}

if ( (ev->code == ABS_Y) || (ev->code == ABS_RX) ) {
priv->raw_y = ev->value;
pos_changed = 1;
}

it's a hack in userspace that works around wrong event reporting. So yes, it works if you're using evtouch but if you want to use any other driver that driver needs the same hack. treating Z as X and RX as Y doesn't work too well for a generic driver such as evdev, which has to deal with devices where RX is a valid axis.

Cheers,
Peter
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