1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
|
.. _incorrectly_enabled_hires:
==============================================================================
Incorrectly enabled high-resolution scroll
==============================================================================
Some devices might announce support for high-resolution scroll wheel by enabling
``REL_WHEEL_HI_RES`` and/or ``REL_HWHEEL_HI_RES`` but never send a
high-resolution scroll event.
When the first low-resolution scroll event is received without any previous
high-resolution event, libinput prints a bug warning with the text **"device
supports high-resolution scroll but only low-resolution events have been
received"** and a link to this page.
.. note:: This warning will be printed only once
In most cases this is a bug on the device firmware, the kernel driver or in a
software used to create user-space devices through uinput.
Once the bug is detected, libinput will start emulating high-resolution scroll
events.
------------------------------------------------------------------------------
Detecting and fixing the issue
------------------------------------------------------------------------------
Events sent by a buggy device can be shown in the
:ref:`libinput record <libinput-record>` output for the device. Notice that
``REL_WHEEL_HI_RES`` and ``REL_HWHEEL_HI_RES`` are set but only ``REL_WHEEL``
events are sent: ::
# Supported Events:
# Event type 0 (EV_SYN)
# Event type 1 (EV_KEY)
# Event code 272 (BTN_LEFT)
# Event type 2 (EV_REL)
# Event code 0 (REL_X)
# Event code 1 (REL_Y)
# Event code 6 (REL_HWHEEL)
# Event code 8 (REL_WHEEL)
# Event code 11 (REL_WHEEL_HI_RES)
# Event code 12 (REL_HWHEEL_HI_RES)
[...]
quirks:
events:
- evdev:
- [ 0, 0, 2, 8, 1] # EV_REL / REL_WHEEL 1
- [ 0, 0, 0, 0, 0] # ------------ SYN_REPORT (0) ---------- +0ms
- evdev:
- [ 0, 15126, 2, 8, 1] # EV_REL / REL_WHEEL 1
- [ 0, 15126, 0, 0, 0] # ------------ SYN_REPORT (0) ---------- +15ms
- evdev:
- [ 0, 30250, 2, 8, 1] # EV_REL / REL_WHEEL 1
- [ 0, 30250, 0, 0, 0] # ------------ SYN_REPORT (0) ---------- +15ms
The issue can be fixed by adding a quirk to unset the ``REL_WHEEL_HI_RES`` and
``REL_HWHEEL_HI_RES`` event codes: ::
AttrEventCodeDisable=REL_WHEEL_HI_RES;REL_HWHEEL_HI_RES;
Please see :ref:`device-quirks` for details.
|
