Bug 483377

Summary:	When screen is turned off for energy saving, can't turn it back on with touch or stylus. Must use a mouse or keyboard.
Product:	[Plasma] kwin	Reporter:	andy <andy>
Component:	input	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED DUPLICATE
Severity:	major	CC:	nate, xaver.hugl
Priority:	NOR	Keywords:	qt6
Version:	6.0.1
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description andy 2024-03-12 20:36:32 UTC

SUMMARY
On an ASUS Flow X16, when in "tent mode" I am using touch and stylus in a drawing app. If on battery, the screen turns off after 5 minutes of inactivity. However, touching the screen or using the stylus anywhere on the screen does not turn the screen back on. I must either flip the keyboard back into laptop mode, or use a USB keyboard/mouse to unblank the screen. When in "laptop mode", the same thing is true - cannot enable the screen with touch or stylus, but can with the laptop's keyboard or trackpad (which are enabled in this mode). The main workflow issue is when not in laptop mode, when there is no physical keyboard or mouse readily available.

STEPS TO REPRODUCE
1. Have a touchscreen device
2. Energy saving settings to Turn off screen after N minutes
3. After N minutes, tap the screen with finger or stylus to try to turn the screen back on
4. If that doesn't work, try using a physical keyboard/mouse (from the laptop or USB if necessary)

Note: with "Touch mode" enabled or disabled is the same result. My preference is with it disabled to not enlarge the UI elements.

OBSERVED RESULT
The screen comes back on with touch/stylus, but it does with a keyboard/mouse

EXPECTED RESULT
The screen should come back on with touch/stylus.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux rolling
KDE Plasma Version: 6.0.1
KDE Frameworks Version: 6.0.0
Qt Version: 6.6.2
Kernel Version: 6.7.8-arch1-1 (64-bit)
Graphics Platform: Wayland


ADDITIONAL INFORMATION

Comment 1 Zamundaaa 2024-03-13 23:44:01 UTC

The code in KWin to wake the screen on a double tap is there, but IIRC it doesn't work everywhere because a lower level component (libinput, the kernel or even the firmware) turns off the touchscreen. I'm not sure we can do anything about it.

Waking the screen on stylus events isn't there yet though and should definitely be implemented.

Comment 2 andy 2024-03-14 02:27:59 UTC

I see. If I set the screen timeout to 1 minute and leave `libinput debug-events` running, then tap the screen a bunch, then press spacebar to turn the screen back on, I see only KEYBOARD_KEY and no TOUCH_* events that I normally see with the screen on.

Trying the same with the stylus, I don't see POINTER_* events either when the screen is off. So it would make sense if this is a lower level kernel/firmware thing.

Comment 3 Zamundaaa 2024-06-25 12:58:14 UTC


*** This bug has been marked as a duplicate of bug 451359 ***