On 12/24/2024, Marek Vasut wrote:
> Commit a25b988ff83f ("drm/bridge: Extend bridge API to disable connector creation")
> added DRM_BRIDGE_ATTACH_NO_CONNECTOR bridge flag and all bridges handle
> this flag in some way since then.
> Newly added bridge drivers must no longer contain the connector creation and
> will fail probing if this flag isn't set.
>
> In order to be able to connect to those newly added bridges as well,
> make use of drm_bridge_connector API and have the connector initialized
> by the display controller.
>
> Based on 2e87bf389e13 ("drm/rockchip: add DRM_BRIDGE_ATTACH_NO_CONNECTOR flag to drm_bridge_attach")
>
> This makes LT9611 work with i.MX8M Plus.
>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> Signed-off-by: Marek Vasut <marex@xxxxxxx>
> ---
> Cc: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
> Cc: David Airlie <airlied@xxxxxxxxx>
> Cc: Fabio Estevam <festevam@xxxxxxxxx>
> 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: Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>
> Cc: Robert Foss <rfoss@xxxxxxxxxx>
> Cc: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Cc: Shawn Guo <shawnguo@xxxxxxxxxx>
> Cc: Simona Vetter <simona@xxxxxxxx>
> Cc: Stefan Agner <stefan@xxxxxxxx>
> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: imx@xxxxxxxxxxxxxxx
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> ---
> V2: Add RB from Dmitry
> ---
> drivers/gpu/drm/mxsfb/Kconfig | 1 +
> drivers/gpu/drm/mxsfb/lcdif_drv.c | 23 ++++++++++++++++++++++-
> 2 files changed, 23 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/mxsfb/Kconfig b/drivers/gpu/drm/mxsfb/Kconfig
> index 264e74f455547..07fb6901996ae 100644
> --- a/drivers/gpu/drm/mxsfb/Kconfig
> +++ b/drivers/gpu/drm/mxsfb/Kconfig
> @@ -30,6 +30,7 @@ config DRM_IMX_LCDIF
> select DRM_CLIENT_SELECTION
> select DRM_MXS
> select DRM_KMS_HELPER
> + select DRM_BRIDGE_CONNECTOR
Select DRM_DISPLAY_HELPER.
> select DRM_GEM_DMA_HELPER
> select DRM_PANEL
> select DRM_PANEL_BRIDGE
> diff --git a/drivers/gpu/drm/mxsfb/lcdif_drv.c b/drivers/gpu/drm/mxsfb/lcdif_drv.c
> index 8ee00f59ca821..40dfbc3e6118e 100644
> --- a/drivers/gpu/drm/mxsfb/lcdif_drv.c
> +++ b/drivers/gpu/drm/mxsfb/lcdif_drv.c
> @@ -17,6 +17,7 @@
> #include <drm/clients/drm_client_setup.h>
> #include <drm/drm_atomic_helper.h>
> #include <drm/drm_bridge.h>
> +#include <drm/drm_bridge_connector.h>
> #include <drm/drm_drv.h>
> #include <drm/drm_encoder.h>
> #include <drm/drm_fbdev_dma.h>
> @@ -48,6 +49,8 @@ static const struct drm_encoder_funcs lcdif_encoder_funcs = {
> static int lcdif_attach_bridge(struct lcdif_drm_private *lcdif)
> {
> struct device *dev = lcdif->drm->dev;
> + struct drm_device *drm = lcdif->drm;
> + struct drm_connector *connector;
> struct device_node *ep;
> struct drm_bridge *bridge;
> int ret;
> @@ -97,13 +100,31 @@ static int lcdif_attach_bridge(struct lcdif_drm_private *lcdif)
> return ret;
> }
>
> - ret = drm_bridge_attach(encoder, bridge, NULL, 0);
> + ret = drm_bridge_attach(encoder, bridge, NULL,
> + DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> if (ret) {
> of_node_put(ep);
> return dev_err_probe(dev, ret,
> "Failed to attach bridge for endpoint%u\n",
> of_ep.id);
> }
> +
> + connector = drm_bridge_connector_init(drm, encoder);
> + if (IS_ERR(connector)) {
of_node_put(ep);
> + ret = PTR_ERR(connector);
> + dev_err_probe(drm->dev, ret,
> + "Failed to initialize bridge connector: %pe\n",
> + connector);
return dev_err_probe(dev, PTR_ERR(connector),
"Failed to initialize bridge connector: %pe\n", connector);
> + return ret;
> + }
> +
> + ret = drm_connector_attach_encoder(connector, encoder);
> + if (ret < 0) {
of_node_put(ep);
> + dev_err_probe(drm->dev, ret,
> + "Failed to attach encoder.\n");
It looks like no one else calls dev_err_probe() when
drm_connector_attach_encoder() fails, plus drm_connector_attach_encoder()
doesn't return -EPROBE_DEFER at all.
> + drm_connector_cleanup(connector);
> + return ret;
> + }
> }
>
> return 0;
--
Regards,
Liu Ying
