2.6.32-stable review patch. If anyone has any objections, please let us know.
------------------
From: Ian Campbell <ian.campbell@citrix.com>
commit 4877c737283813bdb4bebfa3168c1585f6e3a8ca upstream.
In general the semantics of IPIs are that they are are expected to
continue functioning after dpm_suspend_noirq().
Specifically I have seen a deadlock between the callfunc IPI and the
stop machine used by xen's do_suspend() routine. If one CPU has already
called dpm_suspend_noirq() then there is a window where it can be sent
a callfunc IPI before all the other CPUs have entered stop_cpu().
If this happens then the first CPU ends up spinning in stop_cpu()
waiting for the other to rendezvous in state STOPMACHINE_PREPARE while
the other is spinning in csd_lock_wait().
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: xen-devel@lists.xensource.com
LKML-Reference: <1280398595-29708-4-git-send-email-ian.campbell@citrix.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/xen/events.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -535,6 +535,7 @@ int bind_ipi_to_irqhandler(enum ipi_vect
if (irq < 0)
return irq;
+ irqflags |= IRQF_NO_SUSPEND;
retval = request_irq(irq, handler, irqflags, devname, dev_id);
if (retval != 0) {
unbind_from_irq(irq);
--
