Re: [PATCH v3] drm/virtio: Add option to disable KMS support

[Dmitry Osipenko]

On 2/27/23 20:38, Rob Clark wrote:
...
> +	if (IS_ENABLED(CONFIG_DRM_VIRTIO_GPU_KMS)) {
> +		/* get display info */
> +		virtio_cread_le(vgdev->vdev, struct virtio_gpu_config,
> +				num_scanouts, &num_scanouts);
> +		vgdev->num_scanouts = min_t(uint32_t, num_scanouts,
> +					    VIRTIO_GPU_MAX_SCANOUTS);
> +		if (!vgdev->num_scanouts) {
> +			/*
> +			 * Having an EDID but no scanouts is non-sensical,
> +			 * but it is permitted to have no scanouts and no
> +			 * EDID (in which case DRIVER_MODESET and
> +			 * DRIVER_ATOMIC are not advertised)
> +			 */
> +			if (vgdev->has_edid) {
> +				DRM_ERROR("num_scanouts is zero\n");
> +				ret = -EINVAL;
> +				goto err_scanouts;
> +			}
> +			dev->driver_features &= ~(DRIVER_MODESET | DRIVER_ATOMIC);

If it's now configurable by host, why do we need the
CONFIG_DRM_VIRTIO_GPU_KMS?

-- 
Best regards,
Dmitry