coresight: etmv4: Counter values not saved on disable

[ Upstream commit 8fa43700f69703f995ea715b76be6fabdd2f05de ]

The counter value registers change during operation, however this change
is not reflected in the values seen by the user in sysfs.

This fixes the issue by reading back the values on disable.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Fixes: 2e1cdfe184b52 ("coresight-etm4x: Adding CoreSight ETM4x driver")
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200716175746.3338735-11-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
index d59e4b1e5ce58db1ac2440ec64d9e4a46a5bf639..942b362a1f220b69dc5bee2d7b95f1242876e2b7 100644 (file)
--- a/drivers/hwtracing/coresight/coresight-etm4x.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x.c
@@ -507,6 +507,12 @@ static void etm4_disable_hw(void *info)
                        readl_relaxed(drvdata->base + TRCSSCSRn(i));
        }
 
+       /* read back the current counter values */
+       for (i = 0; i < drvdata->nr_cntr; i++) {
+               config->cntr_val[i] =
+                       readl_relaxed(drvdata->base + TRCCNTVRn(i));
+       }
+
        coresight_disclaim_device_unlocked(drvdata->base);
 
        CS_LOCK(drvdata->base);