| From 4877c737283813bdb4bebfa3168c1585f6e3a8ca Mon Sep 17 00:00:00 2001 |
| From: Ian Campbell <ian.campbell@citrix.com> |
| Date: Thu, 29 Jul 2010 11:16:35 +0100 |
| Subject: xen: Do not suspend IPI IRQs. |
| |
| 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 |
| @@ -536,6 +536,7 @@ 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); |
