From 8d5999df35314607c38fbd6bdd709e25c3a4eeab Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Thu, 7 Aug 2014 17:06:06 +0100 Subject: [PATCH] x86/xen: resume timer irqs early If the timer irqs are resumed during device resume it is possible in certain circumstances for the resume to hang early on, before device interrupts are resumed. For an Ubuntu 14.04 PVHVM guest this would occur in ~0.5% of resume attempts. It is not entirely clear what is occuring the point of the hang but I think a task necessary for the resume calls schedule_timeout(), waiting for a timer interrupt (which never arrives). This failure may require specific tasks to be running on the other VCPUs to trigger (processes are not frozen during a suspend/resume if PREEMPT is disabled). Add IRQF_EARLY_RESUME to the timer interrupts so they are resumed in syscore_resume(). Signed-off-by: David Vrabel Reviewed-by: Boris Ostrovsky Cc: stable@vger.kernel.org --- arch/x86/xen/time.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 7b78f88c1707..5718b0b58b60 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -444,7 +444,7 @@ void xen_setup_timer(int cpu) irq = bind_virq_to_irqhandler(VIRQ_TIMER, cpu, xen_timer_interrupt, IRQF_PERCPU|IRQF_NOBALANCING|IRQF_TIMER| - IRQF_FORCE_RESUME, + IRQF_FORCE_RESUME|IRQF_EARLY_RESUME, name, NULL); (void)xen_set_irq_priority(irq, XEN_IRQ_PRIORITY_MAX);