Re: [PATCH V3 1/5] drm/vkms: Avoid assigning 0 for possible_crtc

[Daniel Vetter <daniel@ffwll.ch>]

On Tue, Jun 25, 2019 at 10:36:18PM -0300, Rodrigo Siqueira wrote:
> When vkms invoke drm_universal_plane_init(), it sets 0 for
> possible_crtcs parameter which means that planes can't be attached to
> any CRTC. It currently works due to some safeguard in the drm_crtc file;
> however, it is possible to identify the problem by trying to append a
> second connector. This patch fixes this issue by modifying
> vkms_plane_init() to accept an index parameter which makes the code a
> little bit more flexible and avoid set zero to possible_crtcs.
> 
> Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

> ---
>  drivers/gpu/drm/vkms/vkms_drv.c    | 2 +-
>  drivers/gpu/drm/vkms/vkms_drv.h    | 4 ++--
>  drivers/gpu/drm/vkms/vkms_output.c | 6 +++---
>  drivers/gpu/drm/vkms/vkms_plane.c  | 4 ++--
>  4 files changed, 8 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
> index cc53ef88a331..966b3d653189 100644
> --- a/drivers/gpu/drm/vkms/vkms_drv.c
> +++ b/drivers/gpu/drm/vkms/vkms_drv.c
> @@ -127,7 +127,7 @@ static int vkms_modeset_init(struct vkms_device *vkmsdev)
>  	dev->mode_config.preferred_depth = 24;
>  	dev->mode_config.helper_private = &vkms_mode_config_helpers;
>  
> -	return vkms_output_init(vkmsdev);
> +	return vkms_output_init(vkmsdev, 0);
>  }
>  
>  static int __init vkms_init(void)
> diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
> index 12b4db7ac641..e2d1aa089dec 100644
> --- a/drivers/gpu/drm/vkms/vkms_drv.h
> +++ b/drivers/gpu/drm/vkms/vkms_drv.h
> @@ -115,10 +115,10 @@ bool vkms_get_vblank_timestamp(struct drm_device *dev, unsigned int pipe,
>  			       int *max_error, ktime_t *vblank_time,
>  			       bool in_vblank_irq);
>  
> -int vkms_output_init(struct vkms_device *vkmsdev);
> +int vkms_output_init(struct vkms_device *vkmsdev, int index);
>  
>  struct drm_plane *vkms_plane_init(struct vkms_device *vkmsdev,
> -				  enum drm_plane_type type);
> +				  enum drm_plane_type type, int index);
>  
>  /* Gem stuff */
>  struct drm_gem_object *vkms_gem_create(struct drm_device *dev,
> diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c
> index 56fb5c2a2315..fb1941a6522c 100644
> --- a/drivers/gpu/drm/vkms/vkms_output.c
> +++ b/drivers/gpu/drm/vkms/vkms_output.c
> @@ -35,7 +35,7 @@ static const struct drm_connector_helper_funcs vkms_conn_helper_funcs = {
>  	.get_modes    = vkms_conn_get_modes,
>  };
>  
> -int vkms_output_init(struct vkms_device *vkmsdev)
> +int vkms_output_init(struct vkms_device *vkmsdev, int index)
>  {
>  	struct vkms_output *output = &vkmsdev->output;
>  	struct drm_device *dev = &vkmsdev->drm;
> @@ -45,12 +45,12 @@ int vkms_output_init(struct vkms_device *vkmsdev)
>  	struct drm_plane *primary, *cursor = NULL;
>  	int ret;
>  
> -	primary = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_PRIMARY);
> +	primary = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_PRIMARY, index);
>  	if (IS_ERR(primary))
>  		return PTR_ERR(primary);
>  
>  	if (enable_cursor) {
> -		cursor = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_CURSOR);
> +		cursor = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_CURSOR, index);
>  		if (IS_ERR(cursor)) {
>  			ret = PTR_ERR(cursor);
>  			goto err_cursor;
> diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
> index 0fceb6258422..18c630cfc485 100644
> --- a/drivers/gpu/drm/vkms/vkms_plane.c
> +++ b/drivers/gpu/drm/vkms/vkms_plane.c
> @@ -176,7 +176,7 @@ static const struct drm_plane_helper_funcs vkms_primary_helper_funcs = {
>  };
>  
>  struct drm_plane *vkms_plane_init(struct vkms_device *vkmsdev,
> -				  enum drm_plane_type type)
> +				  enum drm_plane_type type, int index)
>  {
>  	struct drm_device *dev = &vkmsdev->drm;
>  	const struct drm_plane_helper_funcs *funcs;
> @@ -198,7 +198,7 @@ struct drm_plane *vkms_plane_init(struct vkms_device *vkmsdev,
>  		funcs = &vkms_primary_helper_funcs;
>  	}
>  
> -	ret = drm_universal_plane_init(dev, plane, 0,
> +	ret = drm_universal_plane_init(dev, plane, 1 << index,
>  				       &vkms_plane_funcs,
>  				       formats, nformats,
>  				       NULL, type, NULL);
> -- 
> 2.21.0

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch