[PATCH 00/10] Synopsys DisplayPort Controller improvements for Rockchip platforms

[Chaoyi Chen]

Hello Sebastian,

On 3/30/2026 7:50 PM, Sebastian Reichel wrote:
> Hello Chaoyi,
> 
> On Mon, Mar 30, 2026 at 09:34:15AM +0800, Chaoyi Chen wrote:
>>> There are two parts, which possibly need some discussion:
>>>
>>>  1. I added a dedicated bridge callback for out-of-band hotplug events,
>>>     which is separate from the hotplug_notify. I have a feeling, that
>>>     there might be a better solution, but haven't found it.
>>
>> Could you explain what an out-of-band hotplug event is?
>>
>> Can't the drivers/usb/typec/altmodes/displayport.c respond to these
>> hot-plug events? Thank you.
> 
> That is what generates the out-of-band hotplug event in the first
> place via drm_connector_oob_hotplug_event(). The oob in that call
> means out of band.
> 
> If you look at that function it calls oob_hotplug_event() callback
> on the DRM connector, which is then implemented by
> drm_bridge_connector_oob_hotplug_event(). This function calls uses
> the normal hpd handling (shared by in-band and out-of-band) and I'm
> patching it, so that the bridges are aware of hpd explicitly being
> provided out-of-band.
> 

Ah, I'm actually more concerned with the specific types of events.
For example, the "explicitly" provided HPD you mentioned here. 
Isn't drm_connector_oob_hotplug_event able to provide those?

I assume you’re looking for an oob event that is propagated along the
bridge chain, rather than at the connector. Is that so? Thank you.

> Greetings,
> 
> -- Sebastian

-- 
Best, 
Chaoyi