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

From	Rob Herring <robh@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [REGRESSION] "drm: convert drivers to use drm_of_find_panel_or_bridge" breaks graphics on hikey
Date	2017-05-05 00:50 +0200
Message-ID	<tDxJn-1iz-1@gated-at.bofh.it> (permalink)
References	<tDxzI-1f6-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Thu, May 4, 2017 at 5:33 PM, John Stultz <john.stultz@linaro.org> 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).

Rob

Thread

[REGRESSION] "drm: convert drivers to use drm_of_find_panel_or_bridge"  breaks graphics on hikey John Stultz <john.stultz@linaro.org> - 2017-05-05 00:40 +0200
  Re: [REGRESSION] "drm: convert drivers to use drm_of_find_panel_or_bridge"  breaks graphics on hikey Rob Herring <robh@kernel.org> - 2017-05-05 00:50 +0200
    Re: [REGRESSION] "drm: convert drivers to use drm_of_find_panel_or_bridge"  breaks graphics on hikey John Stultz <john.stultz@linaro.org> - 2017-05-05 00:50 +0200

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