Re: [patch 4/8] ACPI: video - convert semaphore to a mutex

[Zhang Rui <rui.zhang@intel.com>]

On Tue, 2007-11-06 at 00:43 +0800, Dmitry Torokhov wrote:
> ACPI: video - convert semaphore to a mutex
> 
> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Zhang Rui <rui.zhang@intel.com>
> ---
>  drivers/acpi/video.c |   21 +++++++++++----------
>  1 file changed, 11 insertions(+), 10 deletions(-)
> 
> Index: work/drivers/acpi/video.c
> ===================================================================
> --- work.orig/drivers/acpi/video.c
> +++ work/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 acp
>                         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(str
>  {
>         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(stru
>         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(stru
>         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(st
>         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(st
>                 kfree(dev);
>         }
> 
> -       up(&video->sem);
> +       mutex_unlock(&video->device_list_lock);
> 
>         return 0;
>  }
> @@ -1924,7 +1925,7 @@ static int acpi_video_bus_add(struct acp
>         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);
> 
> --
> Dmitry
> 
>