[PATCH v1 6/6] perf cs-etm: Generate branch sample for CS_ETM_TRACE_ON packet

[Leo Yan]

CS_ETM_TRACE_ON packet itself can give the info that there have a
discontinuity in the trace, this patch is to add branch sample for
CS_ETM_TRACE_ON packet if it is inserted in the middle of CS_ETM_RANGE
packets; as result we can have hint for the trace discontinuity.

Signed-off-by: Leo Yan <leo....@linaro.org>
---
 tools/perf/util/cs-etm.c | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index d3b7942..2ae6402 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -910,13 +910,23 @@ static int cs_etm__sample(struct cs_etm_queue *etmq)
                etmq->period_instructions = instrs_over;
        }
 
-       if (etm->sample_branches &&
-           etmq->prev_packet &&
-           etmq->prev_packet->sample_type == CS_ETM_RANGE &&
-           etmq->prev_packet->last_instr_taken_branch) {
-               ret = cs_etm__synth_branch_sample(etmq);
-               if (ret)
-                       return ret;
+       if (etm->sample_branches && etmq->prev_packet) {
+               bool generate_sample = false;
+
+               /* Generate sample for tracing on packet */
+               if (etmq->prev_packet->sample_type == CS_ETM_TRACE_ON)
+                       generate_sample = true;
+
+               /* Generate sample for branch taken packet */
+               if (etmq->prev_packet->sample_type == CS_ETM_RANGE &&
+                   etmq->prev_packet->last_instr_taken_branch)
+                       generate_sample = true;
+
+               if (generate_sample) {
+                       ret = cs_etm__synth_branch_sample(etmq);
+                       if (ret)
+                               return ret;
+               }
        }
 
        if (etm->sample_branches || etm->synth_opts.last_branch) {
-- 
2.7.4