Re: [PATCH 4/8] drm/bridge: dw-hdmi: document the output_port field

From: Damon Ding

Date: Thu Mar 26 2026 - 05:32:09 EST


On 3/26/2026 3:25 PM, Liu Ying wrote:
Hi Luca,

On Fri, Mar 20, 2026 at 11:46:15AM +0100, Luca Ceresoli wrote:
The meaning of this flag may not be obvious at first sight.

Signed-off-by: Luca Ceresoli <luca.ceresoli@xxxxxxxxxxx>
---
include/drm/bridge/dw_hdmi.h | 5 +++++
1 file changed, 5 insertions(+)


First of all, these changes related to the DW HDMI controller work well when tested on RK3399 HDMI.

diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
index 336f062e1f9d..45f6ba1a8ee1 100644
--- a/include/drm/bridge/dw_hdmi.h
+++ b/include/drm/bridge/dw_hdmi.h
@@ -126,6 +126,11 @@ struct dw_hdmi_phy_ops {
struct dw_hdmi_plat_data {
struct regmap *regm;
+ /*
+ * The HDMI output port number (which must be 1) if it is described

I'd rephrase:
The HDMI output port number must be 1 ...


Yes, the output port number should be 1, but I found that the output port number in the Rockchip-side dw-hdmi driver remains 0.

Therefore, it may be better to adapt the dw-hdmi drivers across all platforms to the bridge-connector architecture simultaneously.

This would allow removing &dw_hdmi_plat_data.output_port and unify the setting of DRM_BRIDGE_ATTACH_NO_CONNECTOR during the attach stage.
(Just as the Analogix DP driver does [0])

[0] https://lore.kernel.org/all/20260319071452.1961274-1-damon.ding@xxxxxxxxxxxxxx/

+ * in the device tree. 0 if the device tree does not describe the
+ * next component (legacy mode).

Maybe be a bit more specific about "legacy mode":
legacy mode without DRM_BRIDGE_ATTACH_NO_CONNECTOR flag when attaching bridge
?

Reviewed-by: Liu Ying <victor.liu@xxxxxxx>

+ */
unsigned int output_port;
unsigned long input_bus_encoding;



Best regards,
Damon