ACPI: video - convert semaphore to a mutex

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 11 insertions, 10 deletions

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 36b64a751676..d54c83d70532 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -29,6 +29,7 @@
 #include <linux/init.h>
 #include <linux/types.h>
 #include <linux/list.h>
+#include <linux/mutex.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/input.h>
@@ -135,8 +136,8 @@ struct acpi_video_bus {
         u8 attached_count;
         struct acpi_video_bus_cap cap;
         struct acpi_video_bus_flags flags;
-        struct semaphore sem;
         struct list_head video_device_list;
+        struct mutex device_list_lock;  /* protects video_device_list */
         struct proc_dir_entry *dir;
         struct input_dev *input;
         char phys[32];  /* for input device */
@@ -1436,9 +1437,9 @@ acpi_video_bus_get_one_device(struct acpi_device *device,
                         return -ENODEV;
                 }
 
-                down(&video->sem);
+                mutex_lock(&video->device_list_lock);
                 list_add_tail(&data->entry, &video->video_device_list);
-                up(&video->sem);
+                mutex_unlock(&video->device_list_lock);
 
                 acpi_video_device_add_fs(device);
 
@@ -1464,12 +1465,12 @@ static void acpi_video_device_rebind(struct acpi_video_bus *video)
 {
         struct acpi_video_device *dev;
 
-        down(&video->sem);
+        mutex_lock(&video->device_list_lock);
 
         list_for_each_entry(dev, &video->video_device_list, entry)
                 acpi_video_device_bind(video, dev);
 
-        up(&video->sem);
+        mutex_unlock(&video->device_list_lock);
 }
 
 /*
@@ -1601,7 +1602,7 @@ static int acpi_video_switch_output(struct acpi_video_bus *video, int event)
         unsigned long state;
         int status = 0;
 
-        down(&video->sem);
+        mutex_lock(&video->device_list_lock);
 
         list_for_each(node, &video->video_device_list) {
                 dev = container_of(node, struct acpi_video_device, entry);
@@ -1619,7 +1620,7 @@ static int acpi_video_switch_output(struct acpi_video_bus *video, int event)
         dev_prev = container_of(node->prev, struct acpi_video_device, entry);
 
  out:
-        up(&video->sem);
+        mutex_unlock(&video->device_list_lock);
 
         switch (event) {
         case ACPI_VIDEO_NOTIFY_CYCLE:
@@ -1738,7 +1739,7 @@ static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
         int status;
         struct acpi_video_device *dev, *next;
 
-        down(&video->sem);
+        mutex_lock(&video->device_list_lock);
 
         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
 
@@ -1755,7 +1756,7 @@ static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
                 kfree(dev);
         }
 
-        up(&video->sem);
+        mutex_unlock(&video->device_list_lock);
 
         return 0;
 }
@@ -1924,7 +1925,7 @@ static int acpi_video_bus_add(struct acpi_device *device)
         if (error)
                 goto err_free_video;
 
-        init_MUTEX(&video->sem);
+        mutex_init(&video->device_list_lock);
         INIT_LIST_HEAD(&video->video_device_list);
 
         acpi_video_bus_get_devices(video, device);