perf_counter: fix fixed-purpose counter support on v2 Intel-PERFMON

[pandora-kernel.git] / arch / x86 / kernel / cpu / perf_counter.c

diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c
index 196b58f..a6878b0 100644 (file)
--- a/arch/x86/kernel/cpu/perf_counter.c
+++ b/arch/x86/kernel/cpu/perf_counter.c
@@ -962,7 +962,13 @@ static int intel_pmu_init(void)
        x86_pmu = intel_pmu;
        x86_pmu.version = version;
        x86_pmu.num_counters = eax.split.num_counters;
-       x86_pmu.num_counters_fixed = edx.split.num_counters_fixed;
+
+       /*
+        * Quirk: v2 perfmon does not report fixed-purpose counters, so
+        * assume at least 3 counters:
+        */
+       x86_pmu.num_counters_fixed = max((int)edx.split.num_counters_fixed, 3);
+
        x86_pmu.counter_bits = eax.split.bit_width;
        x86_pmu.counter_mask = (1ULL << eax.split.bit_width) - 1;