[PATCH v2] drm/vkms: Remove index parameter from init_vkms_output

Maíra Canal mairacanal at riseup.net
Sat Oct 26 15:22:02 UTC 2024


Hi Louis,

On 10/10/24 14:27, Louis Chauvet wrote:
> VKMS currently supports only one CRTC, so it make no sense to have this
> index configurable. To avoid issues, replace this hardcoded index by
> drm_crtc_mask when applicable.
> 
> There is no need to manually set a crtc mask on primary and cursor plane
> as it is automatically set by drmm_crtc_alloc_with_planes.
> 
> In addition, this will remove the use of an uninitialized structure in
> vkms_add_overlay_plane. This currently works by chance because two things:
> - vkms_plane_init always set a possible_crtcs value, so the problematic
>    branch is never used;
> - drm_crtc_mask on an kzalloc'd drm_crtc returns BIT(0), and the VKMS CRTC
>    always have this id.
> 
> Signed-off-by: Louis Chauvet <louis.chauvet at bootlin.com>
> ---
> Changes in v2:
> - Applied comments from José
> - Link to v1: https://lore.kernel.org/r/20240906-vkms-remove-index-v1-1-3cfedd8ccb2f@bootlin.com
> ---
>   drivers/gpu/drm/vkms/vkms_drv.c    |  2 +-
>   drivers/gpu/drm/vkms/vkms_drv.h    |  8 ++----
>   drivers/gpu/drm/vkms/vkms_output.c | 54 ++++++++++++++------------------------
>   drivers/gpu/drm/vkms/vkms_plane.c  |  4 +--
>   4 files changed, 24 insertions(+), 44 deletions(-)
> 
> diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
> index 2d1e95cb66e5..0f6805b9fe7b 100644
> --- a/drivers/gpu/drm/vkms/vkms_drv.c
> +++ b/drivers/gpu/drm/vkms/vkms_drv.c
> @@ -174,7 +174,7 @@ static int vkms_modeset_init(struct vkms_device *vkmsdev)
>   	dev->mode_config.preferred_depth = 0;
>   	dev->mode_config.helper_private = &vkms_mode_config_helpers;
>   
> -	return vkms_output_init(vkmsdev, 0);
> +	return vkms_output_init(vkmsdev);
>   }
>   
>   static int vkms_create(struct vkms_config *config)
> diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
> index 672fe191e239..036101ee4ea1 100644
> --- a/drivers/gpu/drm/vkms/vkms_drv.h
> +++ b/drivers/gpu/drm/vkms/vkms_drv.h
> @@ -212,21 +212,17 @@ int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
>    * vkms_output_init() - Initialize all sub-components needed for a VKMS device.
>    *
>    * @vkmsdev: VKMS device to initialize
> - * @index: CRTC which can be attached to the planes. The caller must ensure that
> - *	   @index is positive and less or equals to 31.
>    */
> -int vkms_output_init(struct vkms_device *vkmsdev, int index);
> +int vkms_output_init(struct vkms_device *vkmsdev);
>   
>   /**
>    * vkms_plane_init() - Initialize a plane
>    *
>    * @vkmsdev: VKMS device containing the plane
>    * @type: type of plane to initialize
> - * @index: CRTC which can be attached to the plane. The caller must ensure that
> - *	   @index is positive and less or equals to 31.
>    */
>   struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
> -				   enum drm_plane_type type, int index);
> +				   enum drm_plane_type type);
>   
>   /* CRC Support */
>   const char *const *vkms_get_crc_sources(struct drm_crtc *crtc,
> diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c
> index 0a5a185aa0b0..5128aa3b2eb6 100644
> --- a/drivers/gpu/drm/vkms/vkms_output.c
> +++ b/drivers/gpu/drm/vkms/vkms_output.c
> @@ -32,29 +32,14 @@ static const struct drm_connector_helper_funcs vkms_conn_helper_funcs = {
>   	.get_modes    = vkms_conn_get_modes,
>   };
>   
> -static int vkms_add_overlay_plane(struct vkms_device *vkmsdev, int index,
> -				  struct drm_crtc *crtc)
> -{
> -	struct vkms_plane *overlay;
> -
> -	overlay = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_OVERLAY, index);
> -	if (IS_ERR(overlay))
> -		return PTR_ERR(overlay);
> -
> -	if (!overlay->base.possible_crtcs)
> -		overlay->base.possible_crtcs = drm_crtc_mask(crtc);
> -
> -	return 0;
> -}
> -
> -int vkms_output_init(struct vkms_device *vkmsdev, int index)
> +int vkms_output_init(struct vkms_device *vkmsdev)
>   {
>   	struct vkms_output *output = &vkmsdev->output;
>   	struct drm_device *dev = &vkmsdev->drm;
>   	struct drm_connector *connector = &output->connector;
>   	struct drm_encoder *encoder = &output->encoder;
>   	struct drm_crtc *crtc = &output->crtc;
> -	struct vkms_plane *primary, *cursor = NULL;
> +	struct vkms_plane *primary, *overlay, *cursor = NULL;
>   	int ret;
>   	int writeback;
>   	unsigned int n;
> @@ -65,34 +50,37 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index)
>   	 * The overlay and cursor planes are not mandatory, but can be used to perform complex
>   	 * composition.
>   	 */
> -	primary = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_PRIMARY, index);
> +	primary = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_PRIMARY);
>   	if (IS_ERR(primary))
>   		return PTR_ERR(primary);
>   
> -	if (vkmsdev->config->overlay) {
> -		for (n = 0; n < NUM_OVERLAY_PLANES; n++) {
> -			ret = vkms_add_overlay_plane(vkmsdev, index, crtc);
> -			if (ret)
> -				return ret;
> -		}
> -	}
> -
>   	if (vkmsdev->config->cursor) {
> -		cursor = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_CURSOR, index);
> +		cursor = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_CURSOR);
>   		if (IS_ERR(cursor))
>   			return PTR_ERR(cursor);
>   	}
>   
> -	/* [1]: Allocation of a CRTC, its index will be BIT(0) = 1 */
>   	ret = vkms_crtc_init(dev, crtc, &primary->base, &cursor->base);
>   	if (ret)
>   		return ret;
>   
> +	if (vkmsdev->config->overlay) {
> +		for (n = 0; n < NUM_OVERLAY_PLANES; n++) {
> +			overlay = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_OVERLAY);
> +			if (IS_ERR(overlay)) {
> +				DRM_DEV_ERROR(dev->dev, "Failed to init vkms plane\n");
> +				ret = PTR_ERR(overlay);
> +				goto err_crtc;
> +			}
> +			overlay->base.possible_crtcs = drm_crtc_mask(crtc);
> +		}
> +	}
> +
>   	ret = drm_connector_init(dev, connector, &vkms_connector_funcs,
>   				 DRM_MODE_CONNECTOR_VIRTUAL);
>   	if (ret) {
>   		DRM_ERROR("Failed to init connector\n");
> -		goto err_connector;
> +		goto err_crtc;
>   	}
>   
>   	drm_connector_helper_add(connector, &vkms_conn_helper_funcs);
> @@ -103,11 +91,7 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index)
>   		DRM_ERROR("Failed to init encoder\n");
>   		goto err_encoder;
>   	}
> -	/*
> -	 * This is a hardcoded value to select crtc for the encoder.
> -	 * BIT(0) here designate the first registered CRTC, the one allocated in [1]
> -	 */
> -	encoder->possible_crtcs = BIT(0);
> +	encoder->possible_crtcs = drm_crtc_mask(crtc);
>   
>   	ret = drm_connector_attach_encoder(connector, encoder);
>   	if (ret) {
> @@ -131,7 +115,7 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index)
>   err_encoder:
>   	drm_connector_cleanup(connector);
>   
> -err_connector:
> +err_crtc:
>   	drm_crtc_cleanup(crtc);

Do we really need `drm_crtc_cleanup`? We are allocating the CRTC with
`drmm_crtc_init_with_planes`.

The rest looks fine to me.

Best Regards,
- Maíra

>   
>   	return ret;
> diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
> index e5c625ab8e3e..ad137c9a75f5 100644
> --- a/drivers/gpu/drm/vkms/vkms_plane.c
> +++ b/drivers/gpu/drm/vkms/vkms_plane.c
> @@ -198,12 +198,12 @@ static const struct drm_plane_helper_funcs vkms_plane_helper_funcs = {
>   };
>   
>   struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
> -				   enum drm_plane_type type, int index)
> +				   enum drm_plane_type type)
>   {
>   	struct drm_device *dev = &vkmsdev->drm;
>   	struct vkms_plane *plane;
>   
> -	plane = drmm_universal_plane_alloc(dev, struct vkms_plane, base, 1 << index,
> +	plane = drmm_universal_plane_alloc(dev, struct vkms_plane, base, 0,
>   					   &vkms_plane_funcs,
>   					   vkms_formats, ARRAY_SIZE(vkms_formats),
>   					   NULL, type, NULL);
> 
> ---
> base-commit: 33c255312660653cf54f8019896b5dca28e3c580
> change-id: 20240906-vkms-remove-index-3a6e04c38e02
> 
> Best regards,


More information about the dri-devel mailing list