[PATCH] staging: unisys: visorbus: Replace semaphore with mutex

[Binoy Jayan]

The semaphore 'visordriver_callback_lock' is a simple mutex, so
it should be written as one. Semaphores are going away in the future.

Signed-off-by: Binoy Jayan <binoy.ja...@linaro.org>
---
 drivers/staging/unisys/include/visorbus.h       |  3 ++-
 drivers/staging/unisys/visorbus/visorbus_main.c | 14 +++++++-------
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/unisys/include/visorbus.h 
b/drivers/staging/unisys/include/visorbus.h
index 9baf1ec..38edca8 100644
--- a/drivers/staging/unisys/include/visorbus.h
+++ b/drivers/staging/unisys/include/visorbus.h
@@ -34,6 +34,7 @@
 #include <linux/poll.h>
 #include <linux/kernel.h>
 #include <linux/uuid.h>
+#include <linux/mutex.h>
 
 #include "periodic_work.h"
 #include "channel.h"
@@ -159,7 +160,7 @@ struct visor_device {
        struct list_head list_all;
        struct periodic_work *periodic_work;
        bool being_removed;
-       struct semaphore visordriver_callback_lock;
+       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 3a147db..93996a5 100644
--- a/drivers/staging/unisys/visorbus/visorbus_main.c
+++ b/drivers/staging/unisys/visorbus/visorbus_main.c
@@ -544,10 +544,10 @@ dev_periodic_work(void *xdev)
        struct visor_device *dev = xdev;
        struct visor_driver *drv = to_visor_driver(dev->device.driver);
 
-       down(&dev->visordriver_callback_lock);
+       mutex_lock(&dev->visordriver_callback_lock);
        if (drv->channel_interrupt)
                drv->channel_interrupt(dev);
-       up(&dev->visordriver_callback_lock);
+       mutex_unlock(&dev->visordriver_callback_lock);
        if (!visor_periodic_work_nextperiod(dev->periodic_work))
                put_device(&dev->device);
 }
@@ -588,7 +588,7 @@ 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);
@@ -598,7 +598,7 @@ visordriver_probe_device(struct device *xdev)
                fix_vbus_dev_info(dev);
        }
 
-       up(&dev->visordriver_callback_lock);
+       mutex_unlock(&dev->visordriver_callback_lock);
        return res;
 }
 
@@ -614,11 +614,11 @@ 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);
@@ -778,7 +778,7 @@ 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);
-- 
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