[PATCH v2 13/27] staging: unisys: visorbus: Make visordriver_callback_lock a mutex

[David Kershner]

From: Bryan Thompson <bryan.thompson@xxxxxxxxxx>

visordriver_callback_lock is just a binary semaphore that logically
makes more sense as a mutex.

Signed-off-by: Bryan Thompson <bryan.thompson@xxxxxxxxxx>
Signed-off-by: David Kershner <david.kershner@xxxxxxxxxx>
Reviewed-by: Tim Sell <Timothy.Sell@xxxxxxxxxx>
---
 drivers/staging/unisys/include/visorbus.h       |  3 ++-
 drivers/staging/unisys/visorbus/visorbus_main.c | 10 +++++-----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/unisys/include/visorbus.h b/drivers/staging/unisys/include/visorbus.h
index 9bb88bb..9da25c0 100644
--- a/drivers/staging/unisys/include/visorbus.h
+++ b/drivers/staging/unisys/include/visorbus.h
@@ -161,7 +161,8 @@ struct visor_device {
 	struct timer_list timer;
 	bool timer_active;
 	bool being_removed;
-	struct semaphore visordriver_callback_lock;
+	/* mutex to serialize visor_driver function callbacks */
+	struct mutex visordriver_callback_lock;
 	bool pausing;
 	bool resuming;
 	u32 chipset_bus_no;
diff --git a/drivers/staging/unisys/visorbus/visorbus_main.c b/drivers/staging/unisys/visorbus/visorbus_main.c
index 24b27ff..44609ee 100644
--- a/drivers/staging/unisys/visorbus/visorbus_main.c
+++ b/drivers/staging/unisys/visorbus/visorbus_main.c
@@ -574,7 +574,7 @@ visordriver_probe_device(struct device *xdev)
 	if (!drv->probe)
 		return -ENODEV;
 
-	down(&dev->visordriver_callback_lock);
+	mutex_lock(&dev->visordriver_callback_lock);
 	dev->being_removed = false;
 
 	res = drv->probe(dev);
@@ -584,7 +584,7 @@ visordriver_probe_device(struct device *xdev)
 		fix_vbus_dev_info(dev);
 	}
 
-	up(&dev->visordriver_callback_lock);
+	mutex_unlock(&dev->visordriver_callback_lock);
 	return res;
 }
 
@@ -600,11 +600,11 @@ visordriver_remove_device(struct device *xdev)
 
 	dev = to_visor_device(xdev);
 	drv = to_visor_driver(xdev->driver);
-	down(&dev->visordriver_callback_lock);
+	mutex_lock(&dev->visordriver_callback_lock);
 	dev->being_removed = true;
 	if (drv->remove)
 		drv->remove(dev);
-	up(&dev->visordriver_callback_lock);
+	mutex_unlock(&dev->visordriver_callback_lock);
 	dev_stop_periodic_work(dev);
 
 	put_device(&dev->device);
@@ -764,7 +764,7 @@ create_visor_device(struct visor_device *dev)
 	POSTCODE_LINUX_4(DEVICE_CREATE_ENTRY_PC, chipset_dev_no, chipset_bus_no,
 			 POSTCODE_SEVERITY_INFO);
 
-	sema_init(&dev->visordriver_callback_lock, 1);	/* unlocked */
+	mutex_init(&dev->visordriver_callback_lock);
 	dev->device.bus = &visorbus_type;
 	dev->device.groups = visorbus_channel_groups;
 	device_initialize(&dev->device);
-- 
1.9.1