GNOME Bugzilla – Bug 778961
Unable to unlock blanked screen from touchscreen
Last modified: 2020-12-10 18:09:39 UTC
Created attachment 346269 [details] xorg logfile 'evtest' from a remote terminal shows that the touchscreen is sensitive but the session requires input from an attached mouse or keyboard to wake the screen. This is Debian Stretch // The touchscreen devices is an eGalax. The machine is configured not to suspend or hibernate. It is only waking the lockscreen from DPMS. I can only wake the monitor by touching a key on the keyboard or mouse. I can see touch events of the touchscreen using the evtest utility from a remote console while the monitor is in DPMS sleep, but those touch events do nothing. Touch events never wake the monitor from DPMS sleep. If I wake the monitor from sleep then I can swipe away the clock screen and login just using the touchscreen.
I confirm the problem. Gnome 3.24, x.org, lenovo X1 yoga 2nd gen.
Seeing the exact same thing, also using eGalax. 'evtest' show events but screen stays off. Gnome 3.20, Xorg
That's as expected. The touchscreen will be disabled when it's turned off. It's expected that at least one button will be available on the device to wake it up. This is implemented in mutter for Wayland: https://bugzilla.gnome.org/show_bug.cgi?id=739397 and in gnome-settings-daemon's power plugin for X11 though we want to move it to mutter as well: https://bugzilla.gnome.org/show_bug.cgi?id=742598 Closing as not being a bug as it's working as designed.
Presumably input deactivation is due to the power consumed by the input mechanism itself? I can see it being a good policy in some scenarios but not others. If it's a mobile device with an exposed screen, you definitely want to suppress wakeup on touch events, but if it's a stationary/plugged-in device, or a device with lots of battery capacity, it may make sense to allow wakeup on touch. And I guess in some cases there may be no other way to do it.
Created attachment 370648 [details] [review] Add touch screen input switch It makes sense to add a switch to let user have a chance to enable touch screen input when screen is off. The default value of switch is to disable touch screen input, user can change this value to enable touch screen input.
You are unlikely to get feedback for a gnome-settings-daemon patch on a closed gnome-shell bug. I suggest you file a merge request on gitlab.gnome.org/GNOME/gnome-settings-daemon/merge_requests instead.
Created attachment 370650 [details] [review] Add touch screen input switch
(In reply to Bastien Nocera from comment #4) > It's expected that at least one button will be available on the device to > wake it up. What kind of expectation is that? In a great amount of cases touch screens are used for exactly that: to substitute keyboards and mouses. Just think of all-in-one pcs or touchscreen terminals with on-screen keyboards etc. This is just how they work all around the world (and how everyone expects them to work): the user steps in front of the screen, touches it to turn it on, then starts working on it. Why would you want to block such a trivial use case? I'm sorry it's really beyond me why you'd ever want to design a system that works like that.
(In reply to f.viktor.t from comment #9) > (In reply to Bastien Nocera from comment #4) > > It's expected that at least one button will be available on the device to > > wake it up. > > What kind of expectation is that? In a great amount of cases touch screens > are used for exactly that: to substitute keyboards and mouses. Just think of > all-in-one pcs or touchscreen terminals with on-screen keyboards etc. This > is just how they work all around the world (and how everyone expects them to > work): the user steps in front of the screen, touches it to turn it on, then > starts working on it. > Why would you want to block such a trivial use case? I'm sorry it's really > beyond me why you'd ever want to design a system that works like that. Why don't you file a new issue instead of yelling at a 2 year old bug? You better change your tone if you expect people to listen though.