[PATCH 19/25] coresight: cti: Don't disable ect device if it's not enabled

[Mathieu Poirier]

From: Tingwei Zhang <tingwei at codeaurora.org>

If associated ect device is not enabled at first place, disable
routine should not be called. Add ect_enabled flag to check whether
ect device is enabled. Fix the issue in below case.  Ect device is
not available when associated coresight device enabled and the
association is established after coresight device is enabled.

Signed-off-by: Mike Leach <mike.leach at linaro.org>
Signed-off-by: Tingwei Zhang <tingwei at codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier at linaro.org>
---
 drivers/hwtracing/coresight/coresight.c | 11 ++++++++---
 include/linux/coresight.h               |  1 +
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index b8b0a20e93c9..711beb92166a 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -244,13 +244,18 @@ coresight_control_assoc_ectdev(struct coresight_device *csdev, bool enable)
 
 	if (!ect_csdev)
 		return 0;
+	if ((!ect_ops(ect_csdev)->enable) || (!ect_ops(ect_csdev)->disable))
+		return 0;
 
 	if (enable) {
-		if (ect_ops(ect_csdev)->enable)
-			ect_ret = ect_ops(ect_csdev)->enable(ect_csdev);
+		ect_ret = ect_ops(ect_csdev)->enable(ect_csdev);
+		if (!ect_ret)
+			csdev->ect_enabled = true;
 	} else {
-		if (ect_ops(ect_csdev)->disable)
+		if (csdev->ect_enabled) {
 			ect_ret = ect_ops(ect_csdev)->disable(ect_csdev);
+			csdev->ect_enabled = false;
+		}
 	}
 
 	/* output warning if ECT enable is preventing trace operation */
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 3bb738f9a326..7d3c87e5b97c 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -208,6 +208,7 @@ struct coresight_device {
 	/* sysfs links between components */
 	int nr_links;
 	bool has_conns_grp;
+	bool ect_enabled; /* true only if associated ect device is enabled */
 };
 
 /*
-- 
2.25.1