[PATCH v2 2/2] drm: remove drm_device_is_unplugged checks in common drm code.

Daniel Vetter daniel at ffwll.ch
Thu Feb 11 08:19:26 UTC 2016


On Wed, Feb 10, 2016 at 03:18:38PM -0800, Haixia Shi wrote:
> When USB cable is disconnected, we mark udl device as unplugged so that
> udl_detect reports connector status as disconnected, but still keep
> the drm device alive until user-space closes it.
> 
> Signed-off-by: Haixia Shi <hshi at chromium.org>
> Reviewed-by: Stéphane Marchesin <marcheu at chromium.org>

Please add more details capturing the discussion, i.e. why exactly this
was done. Also, has Stephane really re-reviewed this new version already?
And please Cc: everyone involved in the previous patch discussion, too.

Thanks, Daniel

> ---
>  drivers/gpu/drm/drm_drv.c           |  6 ------
>  drivers/gpu/drm/drm_fops.c          |  2 --
>  drivers/gpu/drm/drm_gem.c           |  3 ---
>  drivers/gpu/drm/drm_ioctl.c         |  3 ---
>  drivers/gpu/drm/drm_vm.c            |  3 ---
>  drivers/gpu/drm/udl/udl_connector.c |  2 +-
>  drivers/gpu/drm/udl/udl_drv.c       |  1 +
>  drivers/gpu/drm/udl/udl_drv.h       |  3 +++
>  drivers/gpu/drm/udl/udl_fb.c        |  2 +-
>  drivers/gpu/drm/udl/udl_main.c      | 15 +++++++++++++++
>  include/drm/drmP.h                  | 14 --------------
>  11 files changed, 21 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 167c8d3..f93ee12 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -376,9 +376,6 @@ struct drm_minor *drm_minor_acquire(unsigned int minor_id)
>  
>  	if (!minor) {
>  		return ERR_PTR(-ENODEV);
> -	} else if (drm_device_is_unplugged(minor->dev)) {
> -		drm_dev_unref(minor->dev);
> -		return ERR_PTR(-ENODEV);
>  	}
>  
>  	return minor;
> @@ -464,9 +461,6 @@ void drm_unplug_dev(struct drm_device *dev)
>  	drm_minor_unregister(dev, DRM_MINOR_CONTROL);
>  
>  	mutex_lock(&drm_global_mutex);
> -
> -	drm_device_set_unplugged(dev);
> -
>  	if (dev->open_count == 0) {
>  		drm_put_dev(dev);
>  	}
> diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
> index 1ea8790..b4332d4 100644
> --- a/drivers/gpu/drm/drm_fops.c
> +++ b/drivers/gpu/drm/drm_fops.c
> @@ -497,8 +497,6 @@ int drm_release(struct inode *inode, struct file *filp)
>  
>  	if (!--dev->open_count) {
>  		retcode = drm_lastclose(dev);
> -		if (drm_device_is_unplugged(dev))
> -			drm_put_dev(dev);
>  	}
>  	mutex_unlock(&drm_global_mutex);
>  
> diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
> index 2e8c77e..c622e32 100644
> --- a/drivers/gpu/drm/drm_gem.c
> +++ b/drivers/gpu/drm/drm_gem.c
> @@ -900,9 +900,6 @@ int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
>  	struct drm_vma_offset_node *node;
>  	int ret;
>  
> -	if (drm_device_is_unplugged(dev))
> -		return -ENODEV;
> -
>  	drm_vma_offset_lock_lookup(dev->vma_offset_manager);
>  	node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,
>  						  vma->vm_pgoff,
> diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
> index 8ce2a0c..f959074 100644
> --- a/drivers/gpu/drm/drm_ioctl.c
> +++ b/drivers/gpu/drm/drm_ioctl.c
> @@ -695,9 +695,6 @@ long drm_ioctl(struct file *filp,
>  
>  	dev = file_priv->minor->dev;
>  
> -	if (drm_device_is_unplugged(dev))
> -		return -ENODEV;
> -
>  	is_driver_ioctl = nr >= DRM_COMMAND_BASE && nr < DRM_COMMAND_END;
>  
>  	if (is_driver_ioctl) {
> diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c
> index f90bd5f..3a68be4 100644
> --- a/drivers/gpu/drm/drm_vm.c
> +++ b/drivers/gpu/drm/drm_vm.c
> @@ -657,9 +657,6 @@ int drm_legacy_mmap(struct file *filp, struct vm_area_struct *vma)
>  	struct drm_device *dev = priv->minor->dev;
>  	int ret;
>  
> -	if (drm_device_is_unplugged(dev))
> -		return -ENODEV;
> -
>  	mutex_lock(&dev->struct_mutex);
>  	ret = drm_mmap_locked(filp, vma);
>  	mutex_unlock(&dev->struct_mutex);
> diff --git a/drivers/gpu/drm/udl/udl_connector.c b/drivers/gpu/drm/udl/udl_connector.c
> index 4709b54..b168f2c 100644
> --- a/drivers/gpu/drm/udl/udl_connector.c
> +++ b/drivers/gpu/drm/udl/udl_connector.c
> @@ -96,7 +96,7 @@ static int udl_mode_valid(struct drm_connector *connector,
>  static enum drm_connector_status
>  udl_detect(struct drm_connector *connector, bool force)
>  {
> -	if (drm_device_is_unplugged(connector->dev))
> +	if (udl_device_is_unplugged(connector->dev))
>  		return connector_status_disconnected;
>  	return connector_status_connected;
>  }
> diff --git a/drivers/gpu/drm/udl/udl_drv.c b/drivers/gpu/drm/udl/udl_drv.c
> index d5728ec..3cbafe7 100644
> --- a/drivers/gpu/drm/udl/udl_drv.c
> +++ b/drivers/gpu/drm/udl/udl_drv.c
> @@ -97,6 +97,7 @@ static void udl_usb_disconnect(struct usb_interface *interface)
>  	drm_connector_unplug_all(dev);
>  	udl_fbdev_unplug(dev);
>  	udl_drop_usb(dev);
> +	udl_device_set_unplugged(dev);
>  	drm_unplug_dev(dev);
>  }
>  
> diff --git a/drivers/gpu/drm/udl/udl_drv.h b/drivers/gpu/drm/udl/udl_drv.h
> index 4a064ef..61e117a 100644
> --- a/drivers/gpu/drm/udl/udl_drv.h
> +++ b/drivers/gpu/drm/udl/udl_drv.h
> @@ -65,6 +65,7 @@ struct udl_device {
>  	atomic_t bytes_identical; /* saved effort with backbuffer comparison */
>  	atomic_t bytes_sent; /* to usb, after compression including overhead */
>  	atomic_t cpu_kcycles_used; /* transpired during pixel processing */
> +	atomic_t unplugged; /* device has been unplugged or gone away */
>  };
>  
>  struct udl_gem_object {
> @@ -140,6 +141,8 @@ int udl_handle_damage(struct udl_framebuffer *fb, int x, int y,
>  		      int width, int height);
>  
>  int udl_drop_usb(struct drm_device *dev);
> +void udl_device_set_unplugged(struct drm_device *dev);
> +int udl_device_is_unplugged(struct drm_device *dev);
>  
>  #define CMD_WRITE_RAW8   "\xAF\x60" /**< 8 bit raw write command. */
>  #define CMD_WRITE_RL8    "\xAF\x61" /**< 8 bit run length command. */
> diff --git a/drivers/gpu/drm/udl/udl_fb.c b/drivers/gpu/drm/udl/udl_fb.c
> index 200419d..df1d53e 100644
> --- a/drivers/gpu/drm/udl/udl_fb.c
> +++ b/drivers/gpu/drm/udl/udl_fb.c
> @@ -325,7 +325,7 @@ static int udl_fb_open(struct fb_info *info, int user)
>  	struct udl_device *udl = dev->dev_private;
>  
>  	/* If the USB device is gone, we don't accept new opens */
> -	if (drm_device_is_unplugged(udl->ddev))
> +	if (udl_device_is_unplugged(udl->ddev))
>  		return -ENODEV;
>  
>  	ufbdev->fb_count++;
> diff --git a/drivers/gpu/drm/udl/udl_main.c b/drivers/gpu/drm/udl/udl_main.c
> index 33dbfb2..f6028a4 100644
> --- a/drivers/gpu/drm/udl/udl_main.c
> +++ b/drivers/gpu/drm/udl/udl_main.c
> @@ -350,3 +350,18 @@ int udl_driver_unload(struct drm_device *dev)
>  	kfree(udl);
>  	return 0;
>  }
> +
> +void udl_device_set_unplugged(struct drm_device *dev)
> +{
> +	struct udl_device *udl = dev->dev_private;
> +	smp_wmb();
> +	atomic_set(&udl->unplugged, 1);
> +}
> +
> +int udl_device_is_unplugged(struct drm_device *dev)
> +{
> +	struct udl_device *udl = dev->dev_private;
> +	int ret = atomic_read(&udl->unplugged);
> +	smp_rmb();
> +	return ret;
> +}
> diff --git a/include/drm/drmP.h b/include/drm/drmP.h
> index d7162cf..40c6099 100644
> --- a/include/drm/drmP.h
> +++ b/include/drm/drmP.h
> @@ -748,7 +748,6 @@ struct drm_device {
>  	struct drm_minor *control;		/**< Control node */
>  	struct drm_minor *primary;		/**< Primary node */
>  	struct drm_minor *render;		/**< Render node */
> -	atomic_t unplugged;			/**< Flag whether dev is dead */
>  	struct inode *anon_inode;		/**< inode for private address-space */
>  	char *unique;				/**< unique name of the device */
>  	/*@} */
> @@ -879,19 +878,6 @@ static __inline__ int drm_core_check_feature(struct drm_device *dev,
>  	return ((dev->driver->driver_features & feature) ? 1 : 0);
>  }
>  
> -static inline void drm_device_set_unplugged(struct drm_device *dev)
> -{
> -	smp_wmb();
> -	atomic_set(&dev->unplugged, 1);
> -}
> -
> -static inline int drm_device_is_unplugged(struct drm_device *dev)
> -{
> -	int ret = atomic_read(&dev->unplugged);
> -	smp_rmb();
> -	return ret;
> -}
> -
>  static inline bool drm_is_render_client(const struct drm_file *file_priv)
>  {
>  	return file_priv->minor->type == DRM_MINOR_RENDER;
> -- 
> 2.7.0.rc3.207.g0ac5344
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch


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