Re: [REGRESSION] "drm: convert drivers to use drm_of_find_panel_or_bridge" breaks graphics on hikey

[John Stultz]

On Thu, May 4, 2017 at 3:42 PM, Rob Herring <robh@xxxxxxxxxx> wrote:
> On Thu, May 4, 2017 at 5:33 PM, John Stultz <john.stultz@xxxxxxxxxx> wrote:
>> Hey folks,
>>   Testing mainline with HiKey, I noticed graphics was no longer
>> properly initializing. I don't seem to get much useful info in the way
>> of errors, its just the kirin drm driver doesn't seem to
>> initialize/bind.
>>
>> Digging through the recent changes I landed on ebc944613567 ("drm:
>> convert drivers to use drm_of_find_panel_or_bridge").  And reverting
>> that patch (which doesn't revert cleanly, but cleanly enough for me to
>> test my device), seems to resolve the issue.
>>
>> I've not been able to root cause the problem, but I wanted to bring it
>> up quickly here, as folks might figure out the error faster then I
>> can.
>
> Looking at the change to HiSilicon code:
>
> -       endpoint = of_graph_get_endpoint_by_regs(np, 1, -1);
> [...]
> +       ret = drm_of_find_panel_or_bridge(np, 0, 0, NULL, &dsi->bridge);
>
> This should be (1,0) rather than (0,0) for (port,endpoint).

Yep. This seems to solve it! Thanks so much!

Do you want to send the oneliner out or should I generate it?

thanks
-john