mjhjmtu

I have ubuntu 18.10 installed on a Z83 board, along with a Dell S2240T touchscreen, with no physical keyboard and mouse (this is for a special application that is a music display on a piano).

This worked previously on 16.04 (on a rPi), specifically the screen could be put in power saver mode, but a touch to the screen (the mouse as it were) would wake it up.

Under 18.01 it is set to "blank" on idle, and that part works fine, but the touch aspect is then removed, e.g. syslog shows:

Oct 19 11:38:15 notes /usr/lib/gdm3/gdm-x-session[1114]: (**) Option "fd" "26"
Oct 19 11:38:15 notes /usr/lib/gdm3/gdm-x-session[1114]: (II) event2 - Weida Hi-Tech CoolTouch System : device removed

Cooltouch is the internal name of the screen. Once that message appears you cannot get a touch to register any activity. Powering the monitor on and off has no effect, nor does unplugging/plugging the USB for the touch (well, I see events, but it does not resume working). A reboot is needed to get it working properly again.

I have tried disabling auto-suspend in usbcore (as in here) with no impact.

If I look here:

# ls -la /sys/bus/usb/devices/../../../devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0
total 0
drwxr-xr-x 5 root root 0 Oct 19 11:01 .
drwxr-xr-x 5 root root 0 Oct 19 11:01 ..
drwxr-xr-x 5 root root 0 Oct 19 11:01 0003:2575:8753.0001
-rw-r--r-- 1 root root 4096 Oct 19 11:01 authorized
-r--r--r-- 1 root root 4096 Oct 19 11:01 bAlternateSetting
-r--r--r-- 1 root root 4096 Oct 19 11:01 bInterfaceClass
-r--r--r-- 1 root root 4096 Oct 19 11:01 bInterfaceNumber
-r--r--r-- 1 root root 4096 Oct 19 11:01 bInterfaceProtocol
-r--r--r-- 1 root root 4096 Oct 19 11:01 bInterfaceSubClass
-r--r--r-- 1 root root 4096 Oct 19 11:01 bNumEndpoints
lrwxrwxrwx 1 root root 0 Oct 19 11:01 driver -> ../../../../../../bus/usb/drivers/usbhid
drwxr-xr-x 3 root root 0 Oct 19 11:01 ep_81
-r--r--r-- 1 root root 4096 Oct 19 11:01 interface
-r--r--r-- 1 root root 4096 Oct 19 11:01 modalias
drwxr-xr-x 2 root root 0 Oct 19 11:01 power
lrwxrwxrwx 1 root root 0 Oct 19 11:01 subsystem -> ../../../../../../bus/usb
-r--r--r-- 1 root root 4096 Oct 19 11:01 supports_autosuspend
-rw-r--r-- 1 root root 4096 Oct 19 11:01 uevent

the device shows as you see, and the supports_autosuspend shows as "1" inside the file.

I have installed tlp and tried blacklisting the device without success (and there's a comment in there that indicates HID devices are auto-blacklisted). The file still said "1", and it still went into a removed state.

I should note that I have no good reason to believe the problem is auto-suspend, it could be something completely different that is causing the device to show removed, but auto-suspend is the best guess I have (especially since it shows enabled but I think should not be).

I think I can set the idle time to NEVER, but I did not want the display on 24x7, that seems pointless.

Note the computer is not going to sleep -- I have that disabled entirely. This is about the idle timeout for the screen, which then blanks. This is not a "wake from sleep" issue, indeed the computer continues to respond to the network and I can log in and look around (from another device).

Any advice how to prevent this "removed"?

Linwood

PS. I do not know if this behaves the same way on 18.04; I am running .10 as it had some fixes for an audio device. I know this monitor, however, worked perfectly on a rPi 3B with 16.04 Mate.

PPS. There are no settings on the monitor to control this, that I can find. And certainly none changed since my 16.04 use.