Bug 83055

Summary:	weston freezes temporarly
Product:	Wayland	Reporter:	memeka <mihailescu2m>
Component:	weston	Assignee:	Wayland bug list <wayland-bugs>
Status:	RESOLVED NOTOURBUG	QA Contact:
Severity:	major
Priority:	medium
Version:	1.5.0
Hardware:	ARM
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:

Description memeka 2014-08-25 11:43:34 UTC

I am running wayland + libhybris + qtwayland + qml-compositor

EGL_PLATFORM=hwcomposer ./qml-compositor -platform hwcomposer -plugin EvdevMouse -plugin EvdevKeyboard

Then I start a nested instance of weston:

EGL_PLATFORM=wayland weston -Swayland-1 --fullscreen --width=1920 --height=1080

For few seconds it runs fine, then weston freezes. No refresh of the screen, mouse doesn't move, keyboard does nothing.

If I engage qml-compositor in any way - for example start another app (which results in wayland becoming a smaller window in an expose-like screen with all apps); or if I move the mouse in the right bottom corner (which again tells qml-compositor to takeFocus()) then weston unfreezes and does all the events - so all keyboard presses will be executed then.

If I run some other app in weston, e.g.:
EGL_PLATFORM=wayland WAYLAND_DISPLAY=wayland-1 /usr/local/lib/xbmc/xbmc.bin - which is a full-screen app - then also that app becomes "frozen"; and engaging qml-compositor will unfreeze it.

Same apps running directly under qml-compositor don't have this issue. Only weston.

Comment 1 memeka 2014-08-25 11:45:24 UTC

This is from running weston under gdb and stopping execution when weston freezes:

Program received signal SIGTSTP, Stopped (user).
0xb6daeb62 in epoll_wait () from /lib/arm-linux-gnueabihf/libc.so.6
(gdb) bt
#0  0xb6daeb62 in epoll_wait () from /lib/arm-linux-gnueabihf/libc.so.6
#1  0xb6fc31c0 in wl_event_loop_dispatch (loop=0x374f8, timeout=timeout@entry=-1) at src/event-loop.c:412
#2  0xb6fc22e0 in wl_display_run (display=display@entry=0x374b0) at src/wayland-server.c:986
#3  0x00016144 in main (argc=1, argv=<optimized out>) at src/compositor.c:4420
(gdb) c
Continuing.

Program received signal SIGTSTP, Stopped (user).
0xb6daeb62 in epoll_wait () from /lib/arm-linux-gnueabihf/libc.so.6
(gdb) c
Continuing.
[20:59:11.399] already in the native mode
[20:59:13.132] already in the native mode
[20:59:14.060] already in the native mode
[20:59:17.956] already in the native mode
[20:59:18.132] already in the native mode

Comment 2 Pekka Paalanen 2014-08-25 12:28:27 UTC

(In reply to comment #1)
> This is from running weston under gdb and stopping execution when weston
> freezes:
> 
> Program received signal SIGTSTP, Stopped (user).
> 0xb6daeb62 in epoll_wait () from /lib/arm-linux-gnueabihf/libc.so.6
> (gdb) bt
> #0  0xb6daeb62 in epoll_wait () from /lib/arm-linux-gnueabihf/libc.so.6
> #1  0xb6fc31c0 in wl_event_loop_dispatch (loop=0x374f8,
> timeout=timeout@entry=-1) at src/event-loop.c:412
> #2  0xb6fc22e0 in wl_display_run (display=display@entry=0x374b0) at
> src/wayland-server.c:986
> #3  0x00016144 in main (argc=1, argv=<optimized out>) at
> src/compositor.c:4420

That is perfectly normal. In IRC you said something about a crash, and getting the backtrace from a crash could be useful.

Comment 3 memeka 2014-08-25 12:43:33 UTC

It's not easy to reproduce the crash, it does not happen often, and only after killing weston on freeze, then start it again, killing it again etc...
I would think the crash is related to some other issue maybe...

Comment 4 Daniel Stone 2018-06-04 09:27:29 UTC

Based on what's written, I strongly suspect that qml-compositor is missing some display flushes (e.g. for frame/release events); we've never previously seen the Wayland backend hanging elsewhere. Please reopen if you can still reproduce and debug.

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