INFO: task hung in tls_sw_cancel_work_tx

[syzbot]

syzbot has bisected this bug to:

commit f75f91574617a3c6fbc821c6b156f5777a59d0ed
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Tue May 15 14:31:49 2018 +0000

    drm/i915: Shrink search list for active timelines

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=121dc6b5e00000
start commit:   90568ecf Merge tag 'kvm-5.6-2' of git://git.kernel.org/pub..
git tree:       upstream
final crash:    https://syzkaller.appspot.com/x/report.txt?x=111dc6b5e00000
console output: https://syzkaller.appspot.com/x/log.txt?x=161dc6b5e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=69fa012479f9a62
dashboard link: https://syzkaller.appspot.com/bug?extid=ba431dd9afc3a918981a
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1036b6b5e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1651f6e9e00000

Reported-by: syzbot+ba431dd9afc3a918981a at syzkaller.appspotmail.com
Fixes: f75f91574617 ("drm/i915: Shrink search list for active timelines")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection