[PATCH v2 2/2] arm64: dts: rockchip: add RK3588 DP carrier from Theobroma Systems

[Damon Ding]

Hi Quentin,

On 7/25/2025 8:29 PM, Quentin Schulz wrote:
> Hi Heiko,
> 
> On 7/23/25 9:09 PM, Heiko Stuebner wrote:
>> From: Heiko Stuebner <heiko.stuebner at cherry.de>
>>
>> The DisplayPort carrier is a very simple baseboard only providing serial,
>> ethernet and a displayport output.
>>
>> But its main functionality is that it routes the Analogix eDP controller
>> to this DisplayPort output, which allows to test that controller simply
>> by hooking it up to a suitable monitor.
>>
>> The Analogix-DP controller supports eDP 1.3 and DP 1.2, so can drive
>> both eDP displays as well as full DP monitors. It does not support DP+
>> so passive DP-to-HDMI adapters won't work.
>>
> 
> I tested this on master (2942242dde896) + v2 of the eDP driver as listed 
> in the cover letter, or with v3 of the eDP driver + 
> 48f05c3b4b701ae7687fd44d462c88b7ac67e952 and in both cases I have weird 
> behaviors.
> 
> First, `reboot` is stuck for a very long time before actually rebooting. 
> I think you have a stacktrace when you tried yourself, I don't so cannot 
> send one.
> 
> Also, I tested on two different DP displays, one has a green tint, the 
> other one purple. When trying out other resolutions with modetest, the 
> kernel would often crash (no trace, just nothing on console, SSH dead). 
> Note that the same HW setup with downstream kernel from https:// 
> git.theobroma-systems.com/tiger-linux.git/log/?h=linux-6.1-stan-rkr3.2- 
> tiger works just fine. I would assume this has nothing to do with this 
> Device Tree patch here but rather the eDP patches missing some bits maybe?
> 
> @Damon do you have some idea?
> 

Apologies for the delayed reply. :-)

Since the patch series has been updated to v6, could you please rebase 
these patches? I will then conduct further investigation into this issue.

> The display with green tint is a Iiyama ProLite XU2294HSU and the one 
> with the purple tint is a Dell P2319H if that helps.
> 
> modetest output: https://paste.debian.net/1387797/.
> modetest output with downstream kernel: https://paste.debian.net/1387798/
> 
> The Device Tree looks good to me otherwise.
> 

Best regards,
Damon