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authorIan Campbell <ian.campbell@citrix.com>2010-07-29 11:16:35 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2010-08-13 13:31:07 -0700
commit925a7e4a56ab113a1703caf76be0311f70d53b89 (patch)
treeaedf0db071c274aa8110d5ffed4ce12afaa82ab8
parent88154b0e0ce03c31f24f76e7bde69bbdd6998018 (diff)
downloadlinux-2.6.34-ux500-925a7e4a56ab113a1703caf76be0311f70d53b89.tar.gz
xen: Do not suspend IPI IRQs.
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>
-rw-r--r--drivers/xen/events.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index db8f506817f..28f133ae76a 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -536,6 +536,7 @@ int bind_ipi_to_irqhandler(enum ipi_vector ipi,
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);