linux-kernel - [PATCH V3 12/18] coresight: tmc: dump system memory content only when needed

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Date:	Fri, 22 Apr 2016 11:14:09 -0600
From:	Mathieu Poirier <mathieu.poirier@...aro.org>
To:	linux-arm-kernel@...ts.infradead.org, Suzuki.Poulose@....com
Cc:	linux-kernel@...r.kernel.org
Subject: [PATCH V3 12/18] coresight: tmc: dump system memory content only when needed

Calling tmc_etf/etr_dump_hw() is required only when operating from
sysFS.  When working from Perf, the system memory is harvested
from the AUX trace API.

Signed-off-by: Mathieu Poirier <mathieu.poirier@...aro.org>
---
 drivers/hwtracing/coresight/coresight-tmc-etf.c | 7 ++++++-
 drivers/hwtracing/coresight/coresight-tmc-etr.c | 7 ++++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index d090a9745c73..25fad93b68d4 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -74,7 +74,12 @@ static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
 	CS_UNLOCK(drvdata->base);
 
 	tmc_flush_and_stop(drvdata);
-	tmc_etb_dump_hw(drvdata);
+	/*
+	 * When operating in sysFS mode the content of the buffer needs to be
+	 * read before the TMC is disabled.
+	 */
+	if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
+		tmc_etb_dump_hw(drvdata);
 	tmc_disable_hw(drvdata);
 
 	CS_LOCK(drvdata->base);
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 8bbbf3ab1387..4b000f4003a2 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -76,7 +76,12 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
 	CS_UNLOCK(drvdata->base);
 
 	tmc_flush_and_stop(drvdata);
-	tmc_etr_dump_hw(drvdata);
+	/*
+	 * When operating in sysFS mode the content of the buffer needs to be
+	 * read before the TMC is disabled.
+	 */
+	if (local_read(&drvdata->mode) == CS_MODE_SYSFS)
+		tmc_etr_dump_hw(drvdata);
 	tmc_disable_hw(drvdata);
 
 	CS_LOCK(drvdata->base);
-- 
2.5.0