[PATCH v2 15/23] coresight: trbe: Report truncated trace on buffer update errors

[Leo Yan]

When arm_trbe_update_buffer() handles a pending interrupt that is
not a wrap event, it discards the buffer by returning zero. The AUX
output is not marked as truncated, so userspace is not informed of
the lost trace.

Set PERF_AUX_FLAG_TRUNCATED before returning zero so perf reports
the trace loss when closing the AUX output.

Signed-off-by: Leo Yan <leo.yan@xxxxxxx>
---
 drivers/hwtracing/coresight/coresight-trbe.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index 1c585b6123df2f20d08747678d836742ce9564cc..ac49098aa08412a23a20d32f84c2e1977ee4a223 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c
@@ -903,6 +903,7 @@ static unsigned long arm_trbe_update_buffer(struct coresight_device *csdev,
 		 * errors and as such buffer is empty.
 		 */
 		if (act != TRBE_FAULT_ACT_WRAP) {
+			perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
 			size = 0;
 			goto done;
 		}

-- 
2.34.1