1 files changed, 5 insertions, 3 deletions

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 7b4f1e871f7c..3eb88ebcec5a 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -178,7 +178,7 @@ static void release_pmc_hardware(void) {}
 
 static bool check_hw_exists(void)
 {
-        u64 val, val_new = 0;
+        u64 val, val_new = ~0;
         int i, reg, ret = 0;
 
         /*
@@ -211,8 +211,9 @@ static bool check_hw_exists(void)
          * that don't trap on the MSR access and always return 0s.
          */
         val = 0xabcdUL;
-        ret = wrmsrl_safe(x86_pmu_event_addr(0), val);
-        ret |= rdmsrl_safe(x86_pmu_event_addr(0), &val_new);
+        reg = x86_pmu_event_addr(0);
+        ret = wrmsrl_safe(reg, val);
+        ret |= rdmsrl_safe(reg, &val_new);
         if (ret || val != val_new)
                 goto msr_fail;
 
@@ -229,6 +230,7 @@ bios_fail:
 
 msr_fail:
         printk(KERN_CONT "Broken PMU hardware detected, using software events only.\n");
+        printk(KERN_ERR "Failed to access perfctr msr (MSR %x is %Lx)\n", reg, val_new);
 
         return false;
 }