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References: <20210525000159.3384921-1-dianders@chromium.org>
 <20210524165920.v8.7.I18e60221f6d048d14d6c50a770b15f356fa75092@changeid> <6e0cd667a8a776e524b42f1535827208@codeaurora.org>
In-Reply-To: <6e0cd667a8a776e524b42f1535827208@codeaurora.org>
From:   Doug Anderson <dianders@chromium.org>
Date:   Mon, 7 Jun 2021 10:07:01 -0700
Message-ID: <CAD=FV=UEUsP4qRB-zj31ykS2UznnY=6WF2pD26=FDnVZy6rxCg@mail.gmail.com>
Subject: Re: [PATCH v8 07/11] drm/panel: panel-simple: Stash DP AUX bus; allow
 using it for DDC
To:     Rajeev Nandan <rajeevny@codeaurora.org>
Cc:     Andrzej Hajda <a.hajda@samsung.com>,
        Neil Armstrong <narmstrong@baylibre.com>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        Jonas Karlman <jonas@kwiboo.se>,
        Sam Ravnborg <sam@ravnborg.org>,
        linux-arm-msm <linux-arm-msm@vger.kernel.org>,
        Linus W <linus.walleij@linaro.org>,
        Lyude Paul <lyude@redhat.com>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Steev Klimaszewski <steev@kali.org>,
        Rob Clark <robdclark@chromium.org>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Thierry Reding <treding@nvidia.com>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>,
        Stephen Boyd <swboyd@chromium.org>,
        Daniel Vetter <daniel@ffwll.ch>,
        David Airlie <airlied@linux.ie>,
        Thierry Reding <thierry.reding@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>
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Precedence: bulk

Hi,

On Fri, Jun 4, 2021 at 9:10 AM <rajeevny@codeaurora.org> wrote:
>
> Hi Doug,
>
> >       panel->no_hpd = of_property_read_bool(dev->of_node, "no-hpd");
> >       if (!panel->no_hpd) {
> > @@ -708,6 +712,8 @@ static int panel_simple_probe(struct device *dev,
> > const struct panel_desc *desc)
> >
> >               if (!panel->ddc)
> >                       return -EPROBE_DEFER;
> > +     } else if (aux) {
> > +             panel->ddc = &aux->ddc;
> >       }
>
> In panel_simple_probe(), the put_device(&panel->ddc->dev) call is
> causing issue when the aux->ddc is used to assign panel->ddc
> It works well when "ddc-i2c-bus" is used to assign panel->ddc
>
> static int panel_simple_probe(...)
> {
> ...
>
> free_ddc:
>          if (panel->ddc)
>                  put_device(&panel->ddc->dev);
>
>          return err;
> }

Thanks for catching! Fixed in v9.


-Doug