[PATCH 4/5] coresight: trbe: Move irq_work queue processing

Suzuki K Poulose suzuki.poulose at arm.com
Mon Jul 12 04:38:29 PDT 2021


The TRBE driver issues the irq_work_run() to ensure that
any pending disable event callback has been processed. But this
is done before we mark the AUX buffer as TRUNCATED, making
the call pointless. Move the call after the current handle
has been closed.

Fixes: 3fbf7f011f24 ("coresight: sink: Add TRBE driver")
Reported-by: Tamas Zsoldos <Tamas.Zsoldos at arm.com>
Cc: Anshuman Khandual <anshuman.khandual at arm.com>
Cc: Mathieu Poirier <mathieu.poirier at linaro.org>
Cc: Mike Leach <mike.leach at linaro.org>
Cc: Peter Zijlstra (Intel) <peterz at infradead.org>
Cc: Leo Yan <leo.yan at linaro.org>
Cc: Will Deacon <will at kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose at arm.com>
---
 drivers/hwtracing/coresight/coresight-trbe.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index ec38cf17b693..c0c264264427 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c
@@ -723,6 +723,14 @@ static void trbe_handle_overflow(struct perf_output_handle *handle)
 	perf_aux_output_flag(handle, PERF_AUX_FLAG_CORESIGHT_FORMAT_RAW |
 				     PERF_AUX_FLAG_TRUNCATED);
 	perf_aux_output_end(handle, size);
+
+	/*
+	 * Ensure perf callbacks have completed. Since we
+	 * always TRUNCATE the buffer on IRQ, the event
+	 * is scheduled to be disabled. Make sure that happens
+	 * as soon as possible.
+	 */
+	irq_work_run();
 }
 
 static bool is_perf_trbe(struct perf_output_handle *handle)
@@ -777,12 +785,6 @@ static irqreturn_t arm_trbe_irq_handler(int irq, void *dev)
 	if (!is_perf_trbe(handle))
 		return IRQ_NONE;
 
-	/*
-	 * Ensure perf callbacks have completed, which may disable
-	 * the trace buffer in response to a TRUNCATION flag.
-	 */
-	irq_work_run();
-
 	act = trbe_get_fault_act(status);
 	switch (act) {
 	case TRBE_FAULT_ACT_WRAP:
-- 
2.24.1




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