[RFC][PATCH] drm: bridge: dw-mipi-dsi: Call modeset in modeset callback

[Marek Vasut]

Doing modeset in .atomic_pre_enable callback instead of dedicated .mode_set
callback does not seem right. Undo this change, which was added as part of
commit 05aa61334592 ("drm: bridge: dw-mipi-dsi: Fix enable/disable of DSI
controller") as it breaks STM32MP15xx LTDC scanout (DSI)->TC358762 DSI-to-DPI
bridge->PT800480 DPI panel pipeline. The original fix for HX8394 panel likely
requires HX8394 panel side fix instead.

Fixes: 05aa61334592 ("drm: bridge: dw-mipi-dsi: Fix enable/disable of DSI controller")
Signed-off-by: Marek Vasut <marex@xxxxxxx>
---
Cc: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
Cc: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxxx>
Cc: Douglas Anderson <dianders@xxxxxxxxxxxx>
Cc: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
Cc: Jonas Karlman <jonas@xxxxxxxxx>
Cc: Laurent Pinchart <Laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: Liu Ying <victor.liu@xxxxxxx>
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: Maxime Ripard <mripard@xxxxxxxxxx>
Cc: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
Cc: Ondrej Jirman <megi@xxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: Robert Foss <rfoss@xxxxxxxxxx>
Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 18 +++---------------
 1 file changed, 3 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index 824fb3c65742e..ca5894393dba4 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -268,7 +268,6 @@ struct dw_mipi_dsi {
 	struct dw_mipi_dsi *master; /* dual-dsi master ptr */
 	struct dw_mipi_dsi *slave; /* dual-dsi slave ptr */
 
-	struct drm_display_mode mode;
 	const struct dw_mipi_dsi_plat_data *plat_data;
 };
 
@@ -1016,25 +1015,15 @@ static void dw_mipi_dsi_mode_set(struct dw_mipi_dsi *dsi,
 		phy_ops->power_on(dsi->plat_data->priv_data);
 }
 
-static void dw_mipi_dsi_bridge_atomic_pre_enable(struct drm_bridge *bridge,
-						 struct drm_bridge_state *old_bridge_state)
-{
-	struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
-
-	/* Power up the dsi ctl into a command mode */
-	dw_mipi_dsi_mode_set(dsi, &dsi->mode);
-	if (dsi->slave)
-		dw_mipi_dsi_mode_set(dsi->slave, &dsi->mode);
-}
-
 static void dw_mipi_dsi_bridge_mode_set(struct drm_bridge *bridge,
 					const struct drm_display_mode *mode,
 					const struct drm_display_mode *adjusted_mode)
 {
 	struct dw_mipi_dsi *dsi = bridge_to_dsi(bridge);
 
-	/* Store the display mode for later use in pre_enable callback */
-	drm_mode_copy(&dsi->mode, adjusted_mode);
+	dw_mipi_dsi_mode_set(dsi, adjusted_mode);
+	if (dsi->slave)
+		dw_mipi_dsi_mode_set(dsi->slave, adjusted_mode);
 }
 
 static void dw_mipi_dsi_bridge_atomic_enable(struct drm_bridge *bridge,
@@ -1090,7 +1079,6 @@ static const struct drm_bridge_funcs dw_mipi_dsi_bridge_funcs = {
 	.atomic_get_input_bus_fmts = dw_mipi_dsi_bridge_atomic_get_input_bus_fmts,
 	.atomic_check		= dw_mipi_dsi_bridge_atomic_check,
 	.atomic_reset		= drm_atomic_helper_bridge_reset,
-	.atomic_pre_enable	= dw_mipi_dsi_bridge_atomic_pre_enable,
 	.atomic_enable		= dw_mipi_dsi_bridge_atomic_enable,
 	.atomic_post_disable	= dw_mipi_dsi_bridge_post_atomic_disable,
 	.mode_set		= dw_mipi_dsi_bridge_mode_set,
-- 
2.43.0