[PATCH 4.4 36/40] mei: return error on notification request to a disconnected client

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>


[ Upstream commit 7c47d2ca0feca767479329da23523ed798acb854 ]

Request for a notification from a disconnected client will be ignored
silently by the FW but the caller should know that the operation hasn't
succeeded.

Signed-off-by: Alexander Usyskin <alexander.usyskin@xxxxxxxxx>
Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/misc/mei/client.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -1300,6 +1300,9 @@ int mei_cl_notify_request(struct mei_cl
 		return -EOPNOTSUPP;
 	}
 
+	if (!mei_cl_is_connected(cl))
+		return -ENODEV;
+
 	rets = pm_runtime_get(dev->dev);
 	if (rets < 0 && rets != -EINPROGRESS) {
 		pm_runtime_put_noidle(dev->dev);