Instead of silently returning an error, print a useful warning.
Reviewed-by: Leo Yan leo.yan@arm.com Tested-by: Leo Yan leo.yan@arm.com Signed-off-by: James Clark james.clark@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; }