[PATCH 5/5] drm: Nerv drm_global_mutex BKL for good drivers

[Chris Wilson]

Quoting Daniel Vetter (2020-01-29 08:24:10)
> @@ -378,9 +409,10 @@ int drm_open(struct inode *inode, struct file *filp)
>         if (IS_ERR(minor))
>                 return PTR_ERR(minor);
>  
> -       mutex_unlock(&drm_global_mutex);
> -
>         dev = minor->dev;
> +       if (drm_dev_needs_global_mutex(dev))
> +               mutex_unlock(&drm_global_mutex);

Too soon, too soon.

> +
>         if (!atomic_fetch_inc(&dev->open_count))
>                 need_setup = 1;
>  
> @@ -398,13 +430,15 @@ int drm_open(struct inode *inode, struct file *filp)
>                 }
>         }
>  
> -       mutex_unlock(&drm_global_mutex);
> +       if (drm_dev_needs_global_mutex(dev))
> +               mutex_unlock(&drm_global_mutex);