diff options
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-trbe.c | 27 |
1 files changed, 21 insertions, 6 deletions
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index 47120d263639..0a9106c15639 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -120,6 +120,25 @@ static void trbe_reset_local(void) write_sysreg_s(0, SYS_TRBSR_EL1); } +static void trbe_report_wrap_event(struct perf_output_handle *handle) +{ + /* + * Mark the buffer to indicate that there was a WRAP event by + * setting the COLLISION flag. This indicates to the user that + * the TRBE trace collection was stopped without stopping the + * ETE and thus there might be some amount of trace that was + * lost between the time the WRAP was detected and the IRQ + * was consumed by the CPU. + * + * Setting the TRUNCATED flag would move the event to STOPPED + * state unnecessarily, even when there is space left in the + * ring buffer. Using the COLLISION flag doesn't have this side + * effect. We only set TRUNCATED flag when there is no space + * left in the ring buffer. + */ + perf_aux_output_flag(handle, PERF_AUX_FLAG_COLLISION); +} + static void trbe_stop_and_truncate_event(struct perf_output_handle *handle) { struct trbe_buf *buf = etm_perf_sink_config(handle); @@ -612,7 +631,7 @@ static unsigned long arm_trbe_update_buffer(struct coresight_device *csdev, * for correct size. Also, mark the buffer truncated. */ write = get_trbe_limit_pointer(); - perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); + trbe_report_wrap_event(handle); } offset = write - base; @@ -708,11 +727,7 @@ static void trbe_handle_overflow(struct perf_output_handle *handle) if (buf->snapshot) handle->head += size; - /* - * Mark the buffer as truncated, as we have stopped the trace - * collection upon the WRAP event, without stopping the source. - */ - perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); + trbe_report_wrap_event(handle); perf_aux_output_end(handle, size); event_data = perf_aux_output_begin(handle, event); if (!event_data) { |