[PATCH] HID: Replace semaphore driver_lock with mutex

[Binoy Jayan]

The semaphore 'driver_lock' is used as 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>
---

This patch is part of a bigger effort to eliminate unwanted
semaphores from the linux kernel.

 drivers/hid/hid-core.c | 10 +++++-----
 include/linux/hid.h    |  2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 37084b6..bf21dac 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2222,7 +2222,7 @@ static int hid_device_probe(struct device *dev)
        const struct hid_device_id *id;
        int ret = 0;
 
-       if (down_interruptible(&hdev->driver_lock))
+       if (mutex_lock_interruptible(&hdev->driver_lock))
                return -EINTR;
        if (down_interruptible(&hdev->driver_input_lock)) {
                ret = -EINTR;
@@ -2254,7 +2254,7 @@ static int hid_device_probe(struct device *dev)
        if (!hdev->io_started)
                up(&hdev->driver_input_lock);
 unlock_driver_lock:
-       up(&hdev->driver_lock);
+       mutex_unlock(&hdev->driver_lock);
        return ret;
 }
 
@@ -2264,7 +2264,7 @@ static int hid_device_remove(struct device *dev)
        struct hid_driver *hdrv;
        int ret = 0;
 
-       if (down_interruptible(&hdev->driver_lock))
+       if (mutex_lock_interruptible(&hdev->driver_lock))
                return -EINTR;
        if (down_interruptible(&hdev->driver_input_lock)) {
                ret = -EINTR;
@@ -2285,7 +2285,7 @@ static int hid_device_remove(struct device *dev)
        if (!hdev->io_started)
                up(&hdev->driver_input_lock);
 unlock_driver_lock:
-       up(&hdev->driver_lock);
+       mutex_unlock(&hdev->driver_lock);
        return ret;
 }
 
@@ -2742,7 +2742,7 @@ struct hid_device *hid_allocate_device(void)
        init_waitqueue_head(&hdev->debug_wait);
        INIT_LIST_HEAD(&hdev->debug_list);
        spin_lock_init(&hdev->debug_list_lock);
-       sema_init(&hdev->driver_lock, 1);
+       mutex_init(&hdev->driver_lock);
        sema_init(&hdev->driver_input_lock, 1);
 
        return hdev;
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 5be325d..1add2b3 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -516,7 +516,7 @@ struct hid_device {                                         
        /* device report descriptor */
        struct hid_report_enum report_enum[HID_REPORT_TYPES];
        struct work_struct led_work;                                    /* 
delayed LED worker */
 
-       struct semaphore driver_lock;                                   /* 
protects the current driver, except during input */
+       struct mutex driver_lock;                                       /* 
protects the current driver, except during input */
        struct semaphore driver_input_lock;                             /* 
protects the current driver */
        struct device dev;                                              /* 
device */
        struct hid_driver *driver;
-- 
Binoy Jayan