Attachment 121379 Details for Bug 93503 – 0001-touchpad-drop-motion-hysteresis.patch

[patch] 0001-touchpad-drop-motion-hysteresis.patch

0001-touchpad-drop-motion-hysteresis.patch (text/plain), 1.97 KB, created by Peter Hutterer on 2016-01-29 06:32:38 UTC

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Creator: Peter Hutterer

Created: 2016-01-29 06:32:38 UTC

Size: 1.97 KB

patch

obsolete

>From fb891dfada898d030cc7cedb9b818ad07a21b02a Mon Sep 17 00:00:00 2001
>From: Peter Hutterer <peter.hutterer@who-t.net>
>Date: Fri, 29 Jan 2016 16:25:31 +1000
>Subject: [PATCH libinput] touchpad: drop motion hysteresis
>
>Some older touchpad devices jitter a fair bit when a finger is resting on the
>touchpad. That's why the hysteresis was introduced in the synaptics driver
>back in 2011. The default value of the hysteresis in the synaptics driver
>ended up being 0, even though the code looks like it's using a fraction of the
>touchpad diagonal. When the hysteresis code was ported to libinput it was
>eventually set to 0.5mm.
>
>Turns out this is still too high and tiny finger motions are either
>nonreactive or quite jumpy, making it hard to select small targets. Drop the
>hysteresis by reducing its margin to 0. I'm leaving the code in place for now
>because this will likely be needed for some devices.
>
>Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
>---
> src/evdev-mt-touchpad.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
>diff --git a/src/evdev-mt-touchpad.c b/src/evdev-mt-touchpad.c
>index f249116..757c7c7 100644
>--- a/src/evdev-mt-touchpad.c
>+++ b/src/evdev-mt-touchpad.c
>@@ -1957,7 +1957,6 @@ tp_init(struct tp_dispatch *tp,
> {
> 	int width, height;
> 	double diagonal;
>-	int res_x, res_y;
> 
> 	tp->base.interface = &tp_interface;
> 	tp->device = device;
>@@ -1971,8 +1970,6 @@ tp_init(struct tp_dispatch *tp,
> 	if (tp_init_slots(tp, device) != 0)
> 		return -1;
> 
>-	res_x = tp->device->abs.absinfo_x->resolution;
>-	res_y = tp->device->abs.absinfo_y->resolution;
> 	width = device->abs.dimensions.x;
> 	height = device->abs.dimensions.y;
> 	diagonal = sqrt(width*width + height*height);
>@@ -1981,8 +1978,8 @@ tp_init(struct tp_dispatch *tp,
> 						       EV_ABS,
> 						       ABS_MT_DISTANCE);
> 
>-	tp->hysteresis_margin.x = res_x/2;
>-	tp->hysteresis_margin.y = res_y/2;
>+	tp->hysteresis_margin.x = 0;
>+	tp->hysteresis_margin.y = 0;
> 
> 	if (tp_init_accel(tp, diagonal) != 0)
> 		return -1;
>-- 
>2.5.0
>

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