[PATCH 02/14] perf cs-etm: Warn for invalid timestamp option

[James Clark]

Instead of silently returning an error, print a useful warning.

Signed-off-by: James Clark <james.clark at linaro.org>
---
 tools/perf/arch/arm/util/cs-etm.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
index d2861d66a661..acfdb3f53821 100644
--- a/tools/perf/arch/arm/util/cs-etm.c
+++ b/tools/perf/arch/arm/util/cs-etm.c
@@ -176,8 +176,11 @@ static int cs_etm_validate_timestamp(struct perf_pmu *cs_etm_pmu, struct evsel *
 	 *  0b01000 Implementation supports a maximum timestamp of 64bits.
 	 */
 	trcidr0 &= GENMASK(28, 24);
-	if (!trcidr0)
+	if (!trcidr0) {
+		pr_err("%s: timestamp not supported by HW, disable with %s/timestamp=0/\n",
+		       CORESIGHT_ETM_PMU_NAME, CORESIGHT_ETM_PMU_NAME);
 		return -EINVAL;
+	}
 
 	return 0;
 }

-- 
2.43.0