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From:   Linus Walleij <linus.walleij@linaro.org>
Date:   Tue, 5 Apr 2022 23:21:08 +0200
Message-ID: <CACRpkdbcoRBS=mDqMfseKDWQLZu-ohtXf1jo0nL_S+AagewRBA@mail.gmail.com>
Subject: Re: [PATCH v3] drm: of: Properly try all possible cases for
 bridge/panel detection
To:     Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Cc:     dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Jagan Teki <jagan@amarulasolutions.com>,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>
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On Tue, Mar 29, 2022 at 3:27 PM Paul Kocialkowski
<paul.kocialkowski@bootlin.com> wrote:

> While bridge/panel detection was initially relying on the usual
> port/ports-based of graph detection, it was recently changed to
> perform the lookup on any child node that is not port/ports
> instead when such a node is available, with no fallback on the
> usual way.
>
> This results in breaking detection when a child node is present
> but does not contain any panel or bridge node, even when the
> usual port/ports-based of graph is there.
>
> In order to support both situations properly, this commit reworks
> the logic to try both options and not just one of the two: it will
> only return -EPROBE_DEFER when both have failed.
>
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> Fixes: 80253168dbfd ("drm: of: Lookup if child node has panel or bridge")

This patch fixes the problems I have on the Ux500 MCDE with DPI
panels such as Janice, so:
Tested-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij