Commit 9380dc33 authored by Ludovic Desroches's avatar Ludovic Desroches Committed by Neil Armstrong
Browse files

drm/panel: simple: restore connector_type fallback 



The switch from devm_kzalloc() + drm_panel_init() to
devm_drm_panel_alloc() introduced a regression.

Several panel descriptors do not set connector_type. For those panels,
panel_simple_probe() used to compute a connector type (currently DPI as a
fallback) and pass that value to drm_panel_init(). After the conversion
to devm_drm_panel_alloc(), the call unconditionally used
desc->connector_type instead, ignoring the computed fallback and
potentially passing DRM_MODE_CONNECTOR_Unknown, which
drm_panel_bridge_add() does not allow.

Move the connector_type validation / fallback logic before the
devm_drm_panel_alloc() call and pass the computed connector_type to
devm_drm_panel_alloc(), so panels without an explicit connector_type
once again get the DPI default.

Signed-off-by: default avatarLudovic Desroches <ludovic.desroches@microchip.com>
Fixes: de04bb00 ("drm/panel/panel-simple: Use the new allocation in place of devm_kzalloc()")
Cc: stable@vger.kernel.org
Reviewed-by: default avatarLuca Ceresoli <luca.ceresoli@bootlin.com>
Link: https://lore.kernel.org/stable/20251126-lcd_panel_connector_type_fix-v2-1-c15835d1f7cb%40microchip.com


Signed-off-by: default avatarNeil Armstrong <neil.armstrong@linaro.org>
Link: https://patch.msgid.link/20251218-lcd_panel_connector_type_fix-v3-1-ddcea6d8d7ef@microchip.com
parent 6ab3d435

drivers/gpu/drm/panel/panel-simple.c

+44 −45
Original line number Diff line number Diff line
@@ -623,49 +623,6 @@ static struct panel_simple *panel_simple_probe(struct device *dev) 
	if (IS_ERR(desc))

		return ERR_CAST(desc);



	panel = devm_drm_panel_alloc(dev, struct panel_simple, base,

				     &panel_simple_funcs, desc->connector_type);

	if (IS_ERR(panel))

		return ERR_CAST(panel);



	panel->desc = desc;



	panel->supply = devm_regulator_get(dev, "power");

	if (IS_ERR(panel->supply))

		return ERR_CAST(panel->supply);



	panel->enable_gpio = devm_gpiod_get_optional(dev, "enable",

						     GPIOD_OUT_LOW);

	if (IS_ERR(panel->enable_gpio))

		return dev_err_cast_probe(dev, panel->enable_gpio,

					  "failed to request GPIO\n");



	err = of_drm_get_panel_orientation(dev->of_node, &panel->orientation);

	if (err) {

		dev_err(dev, "%pOF: failed to get orientation %d\n", dev->of_node, err);

		return ERR_PTR(err);

	}



	ddc = of_parse_phandle(dev->of_node, "ddc-i2c-bus", 0);

	if (ddc) {

		panel->ddc = of_find_i2c_adapter_by_node(ddc);

		of_node_put(ddc);



		if (!panel->ddc)

			return ERR_PTR(-EPROBE_DEFER);

	}



	if (!of_device_is_compatible(dev->of_node, "panel-dpi") &&

	    !of_get_display_timing(dev->of_node, "panel-timing", &dt))

		panel_simple_parse_panel_timing_node(dev, panel, &dt);



	if (desc->connector_type == DRM_MODE_CONNECTOR_LVDS) {

		/* Optional data-mapping property for overriding bus format */

		err = panel_simple_override_nondefault_lvds_datamapping(dev, panel);

		if (err)

			goto free_ddc;

	}



	connector_type = desc->connector_type;

	/* Catch common mistakes for panels. */

	switch (connector_type) {
@@ -690,8 +647,7 @@ static struct panel_simple *panel_simple_probe(struct device *dev) 
		break;

	case DRM_MODE_CONNECTOR_eDP:

		dev_warn(dev, "eDP panels moved to panel-edp\n");

		err = -EINVAL;

		goto free_ddc;

		return ERR_PTR(-EINVAL);

	case DRM_MODE_CONNECTOR_DSI:

		if (desc->bpc != 6 && desc->bpc != 8)

			dev_warn(dev, "Expected bpc in {6,8} but got: %u\n", desc->bpc);
@@ -720,6 +676,49 @@ static struct panel_simple *panel_simple_probe(struct device *dev) 
		break;

	}



	panel = devm_drm_panel_alloc(dev, struct panel_simple, base,

				     &panel_simple_funcs, connector_type);

	if (IS_ERR(panel))

		return ERR_CAST(panel);



	panel->desc = desc;



	panel->supply = devm_regulator_get(dev, "power");

	if (IS_ERR(panel->supply))

		return ERR_CAST(panel->supply);



	panel->enable_gpio = devm_gpiod_get_optional(dev, "enable",

						     GPIOD_OUT_LOW);

	if (IS_ERR(panel->enable_gpio))

		return dev_err_cast_probe(dev, panel->enable_gpio,

					  "failed to request GPIO\n");



	err = of_drm_get_panel_orientation(dev->of_node, &panel->orientation);

	if (err) {

		dev_err(dev, "%pOF: failed to get orientation %d\n", dev->of_node, err);

		return ERR_PTR(err);

	}



	ddc = of_parse_phandle(dev->of_node, "ddc-i2c-bus", 0);

	if (ddc) {

		panel->ddc = of_find_i2c_adapter_by_node(ddc);

		of_node_put(ddc);



		if (!panel->ddc)

			return ERR_PTR(-EPROBE_DEFER);

	}



	if (!of_device_is_compatible(dev->of_node, "panel-dpi") &&

	    !of_get_display_timing(dev->of_node, "panel-timing", &dt))

		panel_simple_parse_panel_timing_node(dev, panel, &dt);



	if (desc->connector_type == DRM_MODE_CONNECTOR_LVDS) {

		/* Optional data-mapping property for overriding bus format */

		err = panel_simple_override_nondefault_lvds_datamapping(dev, panel);

		if (err)

			goto free_ddc;

	}



	dev_set_drvdata(dev, panel);



	/*