[PATCH v13 02/28] coresight: Handle helper enable failure properly

[Leo Yan]

If a helper fails to be enabled, unwind any helpers that were already
enabled earlier in the loop. This avoids leaving partially enabled
helpers behind.

Fixes: 6148652807ba ("coresight: Enable and disable helper devices adjacent to the path")
Reviewed-by: Yeoreum Yun <yeoreum.yun at arm.com>
Reviewed-by: James Clark <james.clark at linaro.org>
Tested-by: James Clark <james.clark at linaro.org>
Tested-by: Jie Gan <jie.gan at oss.qualcomm.com>
Signed-off-by: Leo Yan <leo.yan at arm.com>
---
 drivers/hwtracing/coresight/coresight-core.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 2105bb8139407bb579ed2517c1eecccda0a9c2d7..256f6a32621b8e086d02427317e5d35d0f29a3c9 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -499,10 +499,19 @@ static int coresight_enable_helpers(struct coresight_device *csdev,
 
 		ret = coresight_enable_helper(helper, mode, path);
 		if (ret)
-			return ret;
+			goto err;
 	}
 
 	return 0;
+
+err:
+	while (i--) {
+		helper = csdev->pdata->out_conns[i]->dest_dev;
+		if (helper && coresight_is_helper(helper))
+			coresight_disable_helper(helper, path);
+	}
+
+	return ret;
 }
 
 int coresight_enable_path(struct coresight_path *path, enum cs_mode mode)

-- 
2.34.1