From 0bebd752f8c8158aad0ede8b8232870d22d09115 Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Thu, 9 Aug 2012 16:45:12 +0100 Subject: cpufreq: P state stats aren't available if there is no cpufreq driver If there is no cpufreq driver (e.g., with an AMD Opteron 8212) then reading the P state statistics causes a deadlock as an uninitialized spinlock is locked in do_get_pm_info(). The spinlock is initialized in cpufreq_statistic_init() which is not called if cpufreq_driver == NULL. Signed-off-by: David Vrabel Committed-by: Jan Beulich xen-unstable changeset: 25706:7fd5facb6084 xen-unstable date: Fri Aug 03 09:50:28 2012 +0200 --- xen/drivers/acpi/pmstat.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/xen/drivers/acpi/pmstat.c b/xen/drivers/acpi/pmstat.c index e0dd9131c6..9eb8451565 100644 --- a/xen/drivers/acpi/pmstat.c +++ b/xen/drivers/acpi/pmstat.c @@ -68,6 +68,8 @@ int do_get_pm_info(struct xen_sysctl_get_pmstat *op) case PMSTAT_PX: if ( !(xen_processor_pmbits & XEN_PROCESSOR_PM_PX) ) return -ENODEV; + if ( !cpufreq_driver ) + return -ENODEV; if ( !pmpt || !(pmpt->perf.init & XEN_PX_INIT) ) return -EINVAL; break; -- cgit v1.2.3