[PATCH v4 11/15] coresight: Control path during CPU idle

[Leo Yan]

Control links and helpers on an activated path during CPU idle. Since
coresight_disable_path_from() does not handle a source device's
helpers, explicitly disable them alongside the source device.

Signed-off-by: Leo Yan <leo.yan at arm.com>
---
 drivers/hwtracing/coresight/coresight-core.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 6c12692efb51c63f3aa9da6f65a349eae1926f4d..73be22c8f315525111f2dafd692e61bc6db85c25 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -1661,11 +1661,31 @@ static bool coresight_pm_is_needed(struct coresight_device *csdev)
 
 static int coresight_pm_save(struct coresight_device *csdev)
 {
-	return coresight_ops(csdev)->pm_save_disable(csdev);
+	int ret;
+
+	if (WARN_ON(!csdev->path))
+		return -EINVAL;
+
+	ret = coresight_ops(csdev)->pm_save_disable(csdev);
+	if (ret)
+		return ret;
+
+	coresight_disable_helpers(csdev, NULL);
+	coresight_disable_path_from(csdev->path, NULL, true);
+	return 0;
 }
 
 static void coresight_pm_restore(struct coresight_device *csdev)
 {
+	if (WARN_ON(!csdev->path))
+		return;
+
+	/*
+	 * During CPU idle, the sink device is not accessed, so it is okay to
+	 * pass a NULL pointer for the 'sink_data' parameter.
+	 */
+	coresight_enable_path_internal(csdev->path, coresight_get_mode(csdev),
+				       NULL, true);
 	coresight_ops(csdev)->pm_restore_enable(csdev);
 }
 

-- 
2.34.1