[PATCH v1 2/4] coresight: add and remove panic callback for sink

[leo.yan@linaro.org (Leo Yan)]

If the sink device has panic callback function, add the panic callback
node for coresight panic dump list when the sink device is enabled;
also cleanup the node when the sink device is disabled.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 drivers/hwtracing/coresight/coresight.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index 0c37356..5928886 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -138,6 +138,13 @@ static int coresight_enable_sink(struct coresight_device *csdev, u32 mode)
 			if (ret)
 				return ret;
 		}
+
+		/* Add kernel panic callback */
+		if (sink_ops(csdev)->panic_cb) {
+			ret = coresight_add_panic_cb(csdev);
+			if (ret)
+				return ret;
+		}
 		csdev->enable = true;
 	}
 
@@ -149,6 +156,10 @@ static int coresight_enable_sink(struct coresight_device *csdev, u32 mode)
 static void coresight_disable_sink(struct coresight_device *csdev)
 {
 	if (atomic_dec_return(csdev->refcnt) == 0) {
+		/* Remove kernel panic callback */
+		if (sink_ops(csdev)->panic_cb)
+			coresight_del_panic_cb(csdev);
+
 		if (sink_ops(csdev)->disable) {
 			sink_ops(csdev)->disable(csdev);
 			csdev->enable = false;
-- 
2.7.4