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@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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 bc0efc1e5b49..b5e5e6ac67eb 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 0c107811a232..7208584d0da7 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);