linux-kernel - [char-misc-next 3/9] mei: bus: unregister callbacks upon me client disable call

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Date:   Fri, 27 Jan 2017 16:32:40 +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-next 3/9] mei: bus: unregister callbacks upon me client disable call

From: Alexander Usyskin <alexander.usyskin@...el.com>

Stop and unregister receive and notification callbacks
from the disable function, to allow its later re-enablement.

Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
---
 drivers/misc/mei/bus.c | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/drivers/misc/mei/bus.c b/drivers/misc/mei/bus.c
index b67f15b53067..cb3e9e0ca049 100644
--- a/drivers/misc/mei/bus.c
+++ b/drivers/misc/mei/bus.c
@@ -499,6 +499,25 @@ int mei_cldev_enable(struct mei_cl_device *cldev)
 EXPORT_SYMBOL_GPL(mei_cldev_enable);
 
 /**
+ * mei_cldev_unregister_callbacks - internal wrapper for unregistering
+ *  callbacks.
+ *
+ * @cldev: client device
+ */
+static void mei_cldev_unregister_callbacks(struct mei_cl_device *cldev)
+{
+	if (cldev->rx_cb) {
+		cancel_work_sync(&cldev->rx_work);
+		cldev->rx_cb = NULL;
+	}
+
+	if (cldev->notif_cb) {
+		cancel_work_sync(&cldev->notif_work);
+		cldev->notif_cb = NULL;
+	}
+}
+
+/**
  * mei_cldev_disable - disable me client device
  *     disconnect form the me client
  *
@@ -519,6 +538,8 @@ int mei_cldev_disable(struct mei_cl_device *cldev)
 
 	bus = cldev->bus;
 
+	mei_cldev_unregister_callbacks(cldev);
+
 	mutex_lock(&bus->device_lock);
 
 	if (!mei_cl_is_connected(cl)) {
@@ -700,14 +721,7 @@ static int mei_cl_device_remove(struct device *dev)
 	if (cldrv->remove)
 		ret = cldrv->remove(cldev);
 
-	if (cldev->rx_cb) {
-		cancel_work_sync(&cldev->rx_work);
-		cldev->rx_cb = NULL;
-	}
-	if (cldev->notif_cb) {
-		cancel_work_sync(&cldev->notif_work);
-		cldev->notif_cb = NULL;
-	}
+	mei_cldev_unregister_callbacks(cldev);
 
 	module_put(THIS_MODULE);
 	dev->driver = NULL;
-- 
2.7.4