Re: [PATCH v3 6/6] drm/ingenic: Attach bridge chain to encoders

From: H. Nikolaus Schaller
Date: Mon Sep 27 2021 - 12:18:44 EST


Hi Paul,

> Am 25.09.2021 um 21:39 schrieb Paul Cercueil <paul@xxxxxxxxxxxxxxx>:
>
>
>
> Le sam., sept. 25 2021 at 21:26:42 +0200, H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> a écrit :
>> Hi Paul,
>>> Am 25.09.2021 um 21:08 schrieb Paul Cercueil <paul@xxxxxxxxxxxxxxx>:
>>> Hi Paul & Nikolaus,
>>> If you spent some time debugging the issue
>> we did ...
>
> By saying that you didn't debug,

We did - but sometimes you don't see the wood for the trees.

> (null) means you're printing a NULL pointer. So I could see that hdmi->next_bridge was NULL.

I remember we did find this, but did not understand that it should be initialized by dw-hdmi.
And because we though that dw-hdmi has it its own connector, it is ok that way.

> The place that sets it is dw_hdmi_parse_dt, which will return early with code 0, before next_bridge is set, if plat_data->output_port == 0, which was your case.

Well, we were still at 5.14 when we did these initial attempts to use hdmi-connector with synopsys.
Back then, there was no dw_hdmi_parse_dt and no output_port.

IAW: we did not even have a chance to make it work on top of 5.14 the hdmi-connector way. And were sucessful.

I just noticed this when trying to backport the last puzzle piece...

Well, it is always difficult to hit a moving target.

> Since your hdmi-connector is wired at port #1, then .output_port should be 1 as well.

Anyways it works now for 5.14.8 (our internal test) and 5.15-rc3.

And v4 of the jz4780 hdmi stuff will follow.

BR and thanks,
Nikolaus