Tablet suspends while playing video or audio in browser

Status changed to 'Confirmed' because the bug affects multiple users.

Thanks for reporting. Please attach /var/log/syslog and /var/log/repowerd.log from an affected device, as these will help us debug the issue.

I’m seeing this in /var/log/syslog when starting the playback of a youtube video in the browser:

Dec 7 09:51:10 ubuntu-phablet dbus[2791]: apparmor="DENIED" operation="dbus_method_call" bus="session" path="/org/freedesktop/ScreenSaver" interface="org.freedesktop.ScreenSaver" member="Inhibit" mask="send" name="org.freedesktop.ScreenSaver" pid=4647 label="webbrowser-app" peer_pid=3088 peer_label="unconfined"

It looks like oxide is using the wrong PowerSaveBlocker implementation. The corresponding code is https://git.launchpad.net/oxide/tree/shared/browser/device/power_save_blocker_linux.cc#n34.

I can’t install the terminal app on my frieza at the moment, but on my arale I’m seeing the following values for those environment variables:

XDG_CURRENT_DESKTOP=Unity
DESKTOP_SESSION=ubuntu-touch
XDG_SESSION_TYPE=mir
GDMSESSION=ubuntu-touch
XDG_SESSION_DESKTOP=ubuntu-touch

Given those values, base::nix::DesktopEnvironment GetDesktopEnvironment() will return DESKTOP_ENVIRONMENT_UNITY, which explains why oxide instantiates the FDO implementation of PowerSaveBlocker.

It appears lightdm is responsible for setting XDG_CURRENT_DESKTOP, and it sets it to the value of the "X-LightDM-DesktopName" key in /usr/share/lightdm/sessions/ubuntu-touch.desktop.

I assume changing that value to e.g. "Unity8" would have lots of undesirable side effects, so we probably need to patch oxide to be cleverer at guessing the desktop environment.