From: Biju Das <biju.das.jz@bp.renesas.com>

The RZ/G2L hardware manual (Rev. 1.50, May 2025), Section 34.4.2.1,
requires display timings to be set after the HS clock is started. Move
rzg2l_mipi_dsi_set_display_timing() from
rzg2l_mipi_dsi_atomic_pre_enable() to rzg2l_mipi_dsi_atomic_enable(),
placing it after rzg2l_mipi_dsi_start_hs_clock(). Drop the unused ret
variable from rzg2l_mipi_dsi_atomic_pre_enable().

Fixes: 5ce16c169a4c ("drm: renesas: rz-du: Add atomic_pre_enable")
Fixes: 7a043f978ed1 ("drm: rcar-du: Add RZ/G2L DSI driver")
Cc: stable@vger.kernel.org
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v2->v3:
 * No change.
v2:
 * New patch
---
 drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
index a87a301326c7..ff95cb9a7de5 100644
--- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
+++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
@@ -1025,29 +1025,33 @@ static void rzg2l_mipi_dsi_atomic_pre_enable(struct drm_bridge *bridge,
 	const struct drm_display_mode *mode;
 	struct drm_connector *connector;
 	struct drm_crtc *crtc;
-	int ret;
 
 	connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
 	crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
 	mode = &drm_atomic_get_new_crtc_state(state, crtc)->adjusted_mode;
 
-	ret = rzg2l_mipi_dsi_startup(dsi, mode);
-	if (ret < 0)
-		return;
-
-	rzg2l_mipi_dsi_set_display_timing(dsi, mode);
+	rzg2l_mipi_dsi_startup(dsi, mode);
 }
 
 static void rzg2l_mipi_dsi_atomic_enable(struct drm_bridge *bridge,
 					 struct drm_atomic_state *state)
 {
 	struct rzg2l_mipi_dsi *dsi = bridge_to_rzg2l_mipi_dsi(bridge);
+	const struct drm_display_mode *mode;
+	struct drm_connector *connector;
+	struct drm_crtc *crtc;
 	int ret;
 
 	ret = rzg2l_mipi_dsi_start_hs_clock(dsi);
 	if (ret < 0)
 		goto err_stop;
 
+	connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
+	crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
+	mode = &drm_atomic_get_new_crtc_state(state, crtc)->adjusted_mode;
+
+	rzg2l_mipi_dsi_set_display_timing(dsi, mode);
+
 	ret = rzg2l_mipi_dsi_start_video(dsi);
 	if (ret < 0)
 		goto err_stop_clock;
-- 
2.43.0

Hi Biju,
Thanks for your patch.

On Mon, Mar 30, 2026 at 11:44:44AM +0100, Biju wrote:
> From: Biju Das <biju.das.jz@bp.renesas.com>
> 
> The RZ/G2L hardware manual (Rev. 1.50, May 2025), Section 34.4.2.1,
> requires display timings to be set after the HS clock is started. Move
> rzg2l_mipi_dsi_set_display_timing() from
> rzg2l_mipi_dsi_atomic_pre_enable() to rzg2l_mipi_dsi_atomic_enable(),
> placing it after rzg2l_mipi_dsi_start_hs_clock(). Drop the unused ret
> variable from rzg2l_mipi_dsi_atomic_pre_enable().
>


Tested-by: Tommaso Merciai <tommaso.merciai.xr@bp.renesas.com>

Kind Regards,
Tommaso

> Fixes: 5ce16c169a4c ("drm: renesas: rz-du: Add atomic_pre_enable")
> Fixes: 7a043f978ed1 ("drm: rcar-du: Add RZ/G2L DSI driver")
> Cc: stable@vger.kernel.org
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> ---
> v2->v3:
>  * No change.
> v2:
>  * New patch
> ---
>  drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c | 16 ++++++++++------
>  1 file changed, 10 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> index a87a301326c7..ff95cb9a7de5 100644
> --- a/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> +++ b/drivers/gpu/drm/renesas/rz-du/rzg2l_mipi_dsi.c
> @@ -1025,29 +1025,33 @@ static void rzg2l_mipi_dsi_atomic_pre_enable(struct drm_bridge *bridge,
>  	const struct drm_display_mode *mode;
>  	struct drm_connector *connector;
>  	struct drm_crtc *crtc;
> -	int ret;
>  
>  	connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
>  	crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
>  	mode = &drm_atomic_get_new_crtc_state(state, crtc)->adjusted_mode;
>  
> -	ret = rzg2l_mipi_dsi_startup(dsi, mode);
> -	if (ret < 0)
> -		return;
> -
> -	rzg2l_mipi_dsi_set_display_timing(dsi, mode);
> +	rzg2l_mipi_dsi_startup(dsi, mode);
>  }
>  
>  static void rzg2l_mipi_dsi_atomic_enable(struct drm_bridge *bridge,
>  					 struct drm_atomic_state *state)
>  {
>  	struct rzg2l_mipi_dsi *dsi = bridge_to_rzg2l_mipi_dsi(bridge);
> +	const struct drm_display_mode *mode;
> +	struct drm_connector *connector;
> +	struct drm_crtc *crtc;
>  	int ret;
>  
>  	ret = rzg2l_mipi_dsi_start_hs_clock(dsi);
>  	if (ret < 0)
>  		goto err_stop;
>  
> +	connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
> +	crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
> +	mode = &drm_atomic_get_new_crtc_state(state, crtc)->adjusted_mode;
> +
> +	rzg2l_mipi_dsi_set_display_timing(dsi, mode);
> +
>  	ret = rzg2l_mipi_dsi_start_video(dsi);
>  	if (ret < 0)
>  		goto err_stop_clock;
> -- 
> 2.43.0
>