Bug 389200

Summary: Session startup hangs on Wayland master
Product: [Plasma] kwin Reporter: Roman Gilg <subdiff>
Component: wayland-genericAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED UPSTREAM    
Severity: normal    
Priority: NOR    
Version First Reported In: git master   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Roman Gilg 2018-01-19 12:31:51 UTC 
That's a bit early, but on Wayland master this patch has landed in December:
https://cgit.freedesktop.org/wayland/wayland/commit/?id=52609ddf79a96fee0465006e2c6339a3a5d23a87

And with this patch our session does not completely launch anymore. The screen is black and I only can see the mouse cursor.

stracing the hanging process shows unsuccessful ppolls:

ppoll([{fd=71, events=POLLIN}, {fd=84, events=POLLIN}, {fd=68, events=POLLIN}, {fd=47, events=POLLIN}, {fd=69, events=POLLIN}, {fd=59, events=POLLIN}, {fd=64, events=POLLIN}, {fd=65, events=POLLIN}, {fd=78, events=POLLIN}, {fd=11, events=POLLIN}, {fd=7, events=POLLIN}, {fd=72, events=POLLIN}, {fd=50, events=POLLIN}, {fd=3, events=POLLIN}], 14, {0, 498000000}, NULL, 8) = 1 ([{fd=3, revents=POLLIN}], left {0, 497985984})
read(3, "\1\0\0\0\0\0\0\0", 8)          = 8
recvmsg(50, 0x7ffd6a29c910, 0)          = -1 EAGAIN (Resource temporarily unavailable)
recvmsg(50, 0x7ffd6a29c910, 0)          = -1 EAGAIN (Resource temporarily unavailable)
Comment 1 Martin Flöser 2018-01-19 19:38:01 UTC 
If this breaks our session it should be reported to Wayland and be adjusted there.
Comment 2 Roman Gilg 2018-01-20 11:37:13 UTC 
Will be fixed upstream by https://patchwork.freedesktop.org/patch/199297/