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: Ludovic Desroches ludovic.desroches@microchip.com Fixes: de04bb0089a9 ("drm/panel/panel-simple: Use the new allocation in place of devm_kzalloc()") --- Hi,

I am not sure whether this regression has already been reported or addressed. If it has, please feel free to drop this patch. --- drivers/gpu/drm/panel/panel-simple.c | 86 ++++++++++++++++++------------------ 1 file changed, 43 insertions(+), 43 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c index da6b71b70a463400fcc45006788f87e97b0c148c..dc41789f6a53c78b928ff39291ab7219a2d835dd 100644 --- a/drivers/gpu/drm/panel/panel-simple.c +++ b/drivers/gpu/drm/panel/panel-simple.c @@ -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) { @@ -720,6 +677,49 @@ 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);

/*

--- base-commit: 88cbd8ac379cf5ce68b7efcfd4d1484a6871ee0b change-id: 20251121-lcd_panel_connector_type_fix-f00fe3766a42

Best regards,