From: Luca Ceresoli luca.ceresoli@bootlin.com

[ Upstream commit b296955b3a740ecc8b3b08e34fd64f1ceabb8fb4 ]

Having an DRM_MODE_CONNECTOR_Unknown connector type is considered bad, and drm_panel_bridge_add_typed() and derivatives are deprecated for this.

drm_panel_init() won't prevent initializing a panel with a DRM_MODE_CONNECTOR_Unknown connector type. Luckily there are no in-tree users doing it, so take this as an opportinuty to document a valid connector type must be passed.

Returning an error if this rule is violated is not possible because drm_panel_init() is a void function. Add at least a warning to make any violations noticeable, especially to non-upstream drivers.

Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Signed-off-by: Luca Ceresoli luca.ceresoli@bootlin.com Signed-off-by: Robert Foss rfoss@kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20250214-drm-assorted-cleanups... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/drm_panel.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index 7fd3de89ed079..acd29b4f43f84 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -49,7 +49,7 @@ static LIST_HEAD(panel_list); * @dev: parent device of the panel * @funcs: panel operations * @connector_type: the connector type (DRM_MODE_CONNECTOR_*) corresponding to - * the panel interface + * the panel interface (must NOT be DRM_MODE_CONNECTOR_Unknown) * * Initialize the panel structure for subsequent registration with * drm_panel_add(). @@ -57,6 +57,9 @@ static LIST_HEAD(panel_list); void drm_panel_init(struct drm_panel *panel, struct device *dev, const struct drm_panel_funcs *funcs, int connector_type) { + if (connector_type == DRM_MODE_CONNECTOR_Unknown) + DRM_WARN("%s: %s: a valid connector type is required!\n", __func__, dev_name(dev)); + INIT_LIST_HEAD(&panel->list); panel->dev = dev; panel->funcs = funcs;