acpi_pm: Clear pmtmr_ioport if acpi_pm initialization fails

If the acpi pm timer throws invalid data, clear pmtmr_ioport
so the pm timer won't accidentally be used.

This was found when using Xen where there is a acpi pm reported,
but gives bogus values, and other code was continuing to try
to use the pm timer after the initialization failed.

[jstultz: Catch additional failure and reword changelog message. ]

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <1295027246-11110-1-git-send-email-johnstul@us.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
index cfb0f5278415..effe7974aa9a 100644
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -202,17 +202,21 @@ static int __init init_acpi_pm_clocksource(void)
                         printk(KERN_INFO "PM-Timer had inconsistent results:"
                                " 0x%#llx, 0x%#llx - aborting.\n",
                                value1, value2);
+                        pmtmr_ioport = 0;
                         return -EINVAL;
                 }
                 if (i == ACPI_PM_READ_CHECKS) {
                         printk(KERN_INFO "PM-Timer failed consistency check "
                                " (0x%#llx) - aborting.\n", value1);
+                        pmtmr_ioport = 0;
                         return -ENODEV;
                 }
         }
 
-        if (verify_pmtmr_rate() != 0)
+        if (verify_pmtmr_rate() != 0){
+                pmtmr_ioport = 0;
                 return -ENODEV;
+        }
 
         return clocksource_register_hz(&clocksource_acpi_pm,
                                                 PMTMR_TICKS_PER_SEC);