CVS commit: src/sys/arch/xen/xen

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Sat Jun 30 14:59:38 UTC 2018

Modified Files:
        src/sys/arch/xen/xen: clock.c

Log Message:
Rearm the Xen timer on resume.

This just moves the timer-arming logic from xen_initclocks into
xen_resumeclocks so that it runs on resume too.

I hypothesize that this is necessary for Xen to resume.  Otherwise,
how could the one-shot timer possibly by rearmed?  On the other hand,
it is conceivable that something automatically rearms it.

This also reorders the initialization so that we establish a timer
interrupt handler first, and _then_ arm the timer.  If the order
matters, it is hard to imagine that the other way is correct:
conceivably, the interrupt could arrive before we've established the
handler, and then there's nothing to rearm it.

Whether this is _sufficient_ for Xen to resume, I don't know.
Symptoms recently reported in
<https://mail-index.netbsd.org/port-xen/2018/06/15/msg009207.html>
look different from how I would expect this to manifest, which is as
a system wedged because there's no no hardclock activity.

ok cherry


To generate a diff of this commit:
cvs rdiff -u -r1.69 -r1.70 src/sys/arch/xen/xen/clock.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.