Re: [PATCH 2/2] drm/rockchip: dw_hdmi_qp: expose "overscan" property

[Maxime Ripard]

On Tue, Jun 02, 2026 at 09:00:40PM +0400, Alexey Charkov wrote:
> Expose the "overscan" connector property as recognized by KWin and the
> likes to compensate for TV overscan cropping.
> 
> The CRTC will use the margin values derived from this overscan percentage
> in its post-composition scaler to add appropriate blank margins on all
> sides of the output image so that the TV doesn't eat up visible content.
> 
> Signed-off-by: Alexey Charkov <alchark@xxxxxxxxxxx>
> ---
>  drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
> index f35484715c2d..fae44d11dbef 100644
> --- a/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
> +++ b/drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c
> @@ -137,10 +137,18 @@ dw_hdmi_qp_rockchip_encoder_atomic_check(struct drm_encoder *encoder,
>  					 struct drm_connector_state *conn_state)
>  {
>  	struct rockchip_hdmi_qp *hdmi = to_rockchip_hdmi_qp(encoder);
> +	const struct drm_display_mode *adj_mode = &crtc_state->adjusted_mode;
>  	struct rockchip_crtc_state *s = to_rockchip_crtc_state(crtc_state);
>  	union phy_configure_opts phy_cfg = {};
> +	unsigned int overscan;
>  	int ret;
>  
> +	overscan = min(conn_state->tv.overscan, 100u);
> +	s->tv_margins.left   = adj_mode->hdisplay * overscan / 200;
> +	s->tv_margins.right  = s->tv_margins.left;
> +	s->tv_margins.top    = adj_mode->vdisplay * overscan / 200;
> +	s->tv_margins.bottom = s->tv_margins.top;
> +
>  	if (hdmi->tmds_char_rate == conn_state->hdmi.tmds_char_rate &&
>  	    s->output_bpc == conn_state->hdmi.output_bpc)
>  		return 0;
> @@ -603,6 +611,14 @@ static int dw_hdmi_qp_rockchip_bind(struct device *dev, struct device *master,
>  		return dev_err_probe(hdmi->dev, PTR_ERR(connector),
>  				     "Failed to init bridge connector\n");
>  
> +	ret = drm_mode_create_tv_properties_legacy(drm, 0, NULL);
> +	if (ret)
> +		return dev_err_probe(dev, ret,
> +				     "Failed to create TV connector properties\n");
> +
> +	drm_object_attach_property(&connector->base,
> +				   drm->mode_config.tv_overscan_property, 0);
> +

As the name suggests, it's a legacy property only ever used for TV. You
should be using drm_mode_create_tv_margin_properties()

Maxime

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