linux-kernel - [char-misc 4.16] mei: set device client to the disconnected state upon suspend.

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Date:   Wed, 14 Feb 2018 14:03:29 +0200
From:   Tomas Winkler <tomas.winkler@...el.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Alexander Usyskin <alexander.usyskin@...el.com>,
        linux-kernel@...r.kernel.org,
        Tomas Winkler <tomas.winkler@...el.com>
Subject: [char-misc 4.16] mei: set device client to the disconnected state upon suspend.

This fixes regression introduced by
commit 8d52af6795c0 ("mei: speed up the power down flow")

In mei_cldev_disable during device power down flow, such as
suspend or system power off, it jumps over disconnecting function
to speed up the power down process, however, because the client is
unlinked from the file_list (mei_cl_unlink) mei_cl_set_disconnected
is not called from mei_cl_all_disconnect leaving resource leaking.
The most visible is reference counter on underlying HW module is
not decreased preventing to remove modules after suspend/resume cycles.

Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
---
 drivers/misc/mei/bus.c    | 6 ------
 drivers/misc/mei/client.c | 6 ++++++
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index 3e5eabdae8d9..772d02922529 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -548,12 +548,6 @@ int mei_cldev_disable(struct mei_cl_device *cldev)
 		goto out;
 	}
 
-	if (bus->dev_state == MEI_DEV_POWER_DOWN) {
-		dev_dbg(bus->dev, "Device is powering down, don't bother with disconnection\n");
-		err = 0;
-		goto out;
-	}
-
 	err = mei_cl_disconnect(cl);
 	if (err < 0)
 		dev_err(bus->dev, "Could not disconnect from the ME client\n");
diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index be64969d986a..7e60c1817c31 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -945,6 +945,12 @@ int mei_cl_disconnect(struct mei_cl *cl)
 		return 0;
 	}
 
+	if (dev->dev_state == MEI_DEV_POWER_DOWN) {
+		cl_dbg(dev, cl, "Device is powering down, don't bother with disconnection\n");
+		mei_cl_set_disconnected(cl);
+		return 0;
+	}
+
 	rets = pm_runtime_get(dev->dev);
 	if (rets < 0 && rets != -EINPROGRESS) {
 		pm_runtime_put_noidle(dev->dev);
-- 
2.14.3