From 6c0d6701a551ac344e63935535db0494110c5f4e Mon Sep 17 00:00:00 2001
From: Alexander Usyskin <alexander.usyskin@intel.com>
Date: Fri, 27 Jan 2017 16:32:42 +0200
Subject: [PATCH] mei: abort waiting for notification on unsupported HW

On legacy HW, pre Skylake, the notifications are not supported,
return -EOPNOTSUPP in mei_cl_notify_get and prevent
waiting indefinitely.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/misc/mei/client.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index ecfaef93457d..923fad39535c 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -1428,6 +1428,11 @@ int mei_cl_notify_get(struct mei_cl *cl, bool block, bool *notify_ev)
 
 	dev = cl->dev;
 
+	if (!dev->hbm_f_ev_supported) {
+		cl_dbg(dev, cl, "notifications not supported\n");
+		return -EOPNOTSUPP;
+	}
+
 	if (!mei_cl_is_connected(cl))
 		return -ENODEV;