Re: [PATCH v8 04/18] drm/bridge: analogix_dp: Add &analogix_dp_plat_data.next_bridge

["Luca Ceresoli" <luca.ceresoli@bootlin.com>]

Hello Damon,

On Wed Dec 17, 2025 at 10:33 AM CET, Damon Ding wrote:
> In order to move the panel/bridge parsing and attachmenet to the
> Analogix side, add component struct drm_bridge *next_bridge to
> platform data struct analogix_dp_plat_data.
>
> The movement makes sense because the panel/bridge should logically
> be positioned behind the Analogix bridge in the display pipeline.
>
> Signed-off-by: Damon Ding <damon.ding@rock-chips.com>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
>
> ---
>
> Changes in v4:
> - Rename the &analogix_dp_plat_data.bridge to
>   &analogix_dp_plat_data.next_bridge
> ---
>  include/drm/bridge/analogix_dp.h | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/include/drm/bridge/analogix_dp.h b/include/drm/bridge/analogix_dp.h
> index cf17646c1310..582357c20640 100644
> --- a/include/drm/bridge/analogix_dp.h
> +++ b/include/drm/bridge/analogix_dp.h
> @@ -27,6 +27,7 @@ static inline bool is_rockchip(enum analogix_dp_devtype type)
>  struct analogix_dp_plat_data {
>  	enum analogix_dp_devtype dev_type;
>  	struct drm_panel *panel;
> +	struct drm_bridge *next_bridge;
>  	struct drm_encoder *encoder;
>  	struct drm_connector *connector;
>  	bool skip_connector;

It took a while to understand why you are adding the next_bridge pointer in
struct analogix_dp_plat_data instead of struct analogix_dp_device, where it
would be more natural. I found an answer in patch 16: with current code you
need to place next_bridge in struct analogix_dp_plat_data because it is
used by user drivers to attach, and those drivers have no access to struct
analogix_dp_device. However patch 16 (which looks a very good cleanup BTW)
next_bridge can be moved to struct analogix_dp_device.

So I'd suggest to move patch 16 before this one if it easily doable, so
that you can introduce next_bridge in struct analogix_dp_device from the
beginning. Should that be impossible, you can send a separate patch to move
next_bridge, after patch 16.

Best regards,
Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com