linux-kernel - Re: [PATCH v7 10/15] drm/rockchip: analogix_dp: Add support to get panel from the DP AUX bus

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAD=FV=WS_2JAKMyFFmrNtaN7-O4dh2hOXHc25FytDxXAjAr+5A@mail.gmail.com>
Date: Mon, 24 Feb 2025 17:42:05 -0800
From: Doug Anderson <dianders@...omium.org>
To: Damon Ding <damon.ding@...k-chips.com>
Cc: heiko@...ech.de, andy.yan@...k-chips.com, hjc@...k-chips.com, 
	robh@...nel.org, krzk+dt@...nel.org, conor+dt@...nel.org, 
	andrzej.hajda@...el.com, neil.armstrong@...aro.org, rfoss@...nel.org, 
	Laurent.pinchart@...asonboard.com, jonas@...boo.se, jernej.skrabec@...il.com, 
	dmitry.baryshkov@...aro.org, sebastian.reichel@...labora.com, 
	cristian.ciocaltea@...labora.com, boris.brezillon@...labora.com, 
	l.stach@...gutronix.de, dri-devel@...ts.freedesktop.org, 
	devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org, 
	linux-rockchip@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v7 10/15] drm/rockchip: analogix_dp: Add support to get
 panel from the DP AUX bus

Hi,

On Mon, Feb 24, 2025 at 12:14 AM Damon Ding <damon.ding@...k-chips.com> wrote:
>
> @@ -392,11 +393,27 @@ static const struct component_ops rockchip_dp_component_ops = {
>         .unbind = rockchip_dp_unbind,
>  };
>
> +static int rockchip_dp_link_panel(struct drm_dp_aux *aux)
> +{
> +       struct analogix_dp_plat_data *plat_data = analogix_dp_aux_to_plat_data(aux);
> +       struct rockchip_dp_device *dp = pdata_encoder_to_dp(plat_data);
> +       int ret;
> +
> +       ret = drm_of_find_panel_or_bridge(dp->dev->of_node, 1, 0, &plat_data->panel, NULL);
> +       if (ret && ret != -ENODEV)
> +               return ret;

Can you explain why you treat -ENODEV as a non-error case here? Maybe
this is for the non-eDP case (AKA the DP case) where there's no
further panels or bridges? Maybe a comment would be helpful to remind
us?


> +       ret = component_add(dp->dev, &rockchip_dp_component_ops);
> +       if (ret)
> +               return ret;
> +
> +       return ret;

nit: the above could just be:

return component_add(dp->dev, &rockchip_dp_component_ops);


> @@ -448,9 +460,16 @@ static int rockchip_dp_probe(struct platform_device *pdev)
>         if (IS_ERR(dp->adp))
>                 return PTR_ERR(dp->adp);
>
> -       ret = component_add(dev, &rockchip_dp_component_ops);
> -       if (ret)
> -               return ret;
> +       ret = devm_of_dp_aux_populate_bus(analogix_dp_get_aux(dp->adp), rockchip_dp_link_panel);
> +       if (ret) {
> +               if (ret != -ENODEV)
> +                       return dev_err_probe(dp->dev, ret,
> +                                            "failed to populate aux bus : %d\n", ret);

IIRC this -ENODEV case is for old legacy panels that aren't listed
under the aux bus in the device tree. Maybe a comment would be helpful
to remind us?

nit: don't need the %d in your error message. dev_err_probe() already
prints the error code.


> +               ret = rockchip_dp_link_panel(analogix_dp_get_aux(dp->adp));
> +               if (ret)
> +                       return ret;
> +       }
>
>         return 0;

You can get rid of a few of your return cases by just returning "ret" here.


-Doug