linux-kernel - [PATCH 02/19] coresight: trbe: Remove redundant disable operation

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Message-Id: <20251201-trbe_buffer_refactor_v1-1-v1-2-7da32b076b28@arm.com>
Date: Mon, 01 Dec 2025 11:21:52 +0000
From: Leo Yan <leo.yan@....com>
To: Suzuki K Poulose <suzuki.poulose@....com>, 
 Mike Leach <mike.leach@...aro.org>, James Clark <james.clark@...aro.org>, 
 Anshuman Khandual <anshuman.khandual@....com>, 
 Yeoreum Yun <yeoreum.yun@....com>, Will Deacon <will@...nel.org>, 
 Mark Rutland <mark.rutland@....com>, Tamas Petz <tamas.petz@....com>, 
 Tamas Zsoldos <tamas.zsoldos@....com>, 
 Arnaldo Carvalho de Melo <acme@...nel.org>, 
 Namhyung Kim <namhyung@...nel.org>, Jiri Olsa <jolsa@...nel.org>, 
 Ian Rogers <irogers@...gle.com>, Adrian Hunter <adrian.hunter@...el.com>
Cc: coresight@...ts.linaro.org, linux-arm-kernel@...ts.infradead.org, 
 linux-kernel@...r.kernel.org, linux-perf-users@...r.kernel.org, 
 Leo Yan <leo.yan@....com>
Subject: [PATCH 02/19] coresight: trbe: Remove redundant disable operation

The trace unit is already disabled when trbe_stop_and_truncate_event()
is called, so draining and stopping the buffer in the function is
redundant.

Remove the unnecessary disable operation and rename the function to
trbe_truncate_event() to better reflect its purpose.

Signed-off-by: Leo Yan <leo.yan@....com>
---
 drivers/hwtracing/coresight/coresight-trbe.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index 0ddb3db0213cf0014e29decfb79da68b0a351b31..2f44e4a65e0ee2b2c8fdd06a51ab01fc57f44a4e 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c
@@ -284,18 +284,10 @@ static void trbe_report_wrap_event(struct perf_output_handle *handle)
 	perf_aux_output_flag(handle, PERF_AUX_FLAG_COLLISION);
 }
 
-static void trbe_stop_and_truncate_event(struct perf_output_handle *handle)
+static void trbe_truncate_event(struct perf_output_handle *handle)
 {
 	struct trbe_buf *buf = etm_perf_sink_config(handle);
 
-	/*
-	 * We cannot proceed with the buffer collection and we
-	 * do not have any data for the current session. The
-	 * etm_perf driver expects to close out the aux_buffer
-	 * at event_stop(). So disable the TRBE here and leave
-	 * the update_buffer() to return a 0 size.
-	 */
-	trbe_drain_and_disable_local(buf->cpudata);
 	perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
 	perf_aux_output_end(handle, 0);
 	*this_cpu_ptr(buf->cpudata->drvdata->handle) = NULL;
@@ -1008,7 +1000,7 @@ static int __arm_trbe_enable(struct trbe_buf *buf,
 	trbe_enable_hw(buf);
 	return 0;
 err:
-	trbe_stop_and_truncate_event(handle);
+	trbe_truncate_event(handle);
 	return ret;
 }
 
@@ -1169,7 +1161,7 @@ static irqreturn_t arm_trbe_irq_handler(int irq, void *dev)
 		trbe_handle_spurious(handle);
 		break;
 	case TRBE_FAULT_ACT_FATAL:
-		trbe_stop_and_truncate_event(handle);
+		trbe_truncate_event(handle);
 		truncated = true;
 		break;
 	}

-- 
2.34.1