Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20210712181209.27023-1-dafna.hirschfeld@collabora.com>
In-Reply-To: <20210712181209.27023-1-dafna.hirschfeld@collabora.com>
From:   Chun-Kuang Hu <chunkuang.hu@kernel.org>
Date:   Mon, 9 Aug 2021 22:20:23 +0800
Message-ID: <CAAOTY__vy0n_Sw+8a_4h7Er_qdt72x964Dc_uunLg88qx8wPGg@mail.gmail.com>
Subject: Re: [PATCH] drm/mediatek: Test component initialization earlier in
 the function mtk_drm_crtc_create
To:     Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Cc:     DRI Development <dri-devel@lists.freedesktop.org>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Collabora Kernel ML <kernel@collabora.com>, dafna3@gmail.com,
        Chun-Kuang Hu <chunkuang.hu@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Enric Balletbo i Serra <enric.balletbo@collabora.com>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

Hi, Dafna:

Dafna Hirschfeld <dafna.hirschfeld@collabora.com> =E6=96=BC 2021=E5=B9=B47=
=E6=9C=8813=E6=97=A5 =E9=80=B1=E4=BA=8C =E4=B8=8A=E5=8D=882:12=E5=AF=AB=E9=
=81=93=EF=BC=9A
>
> The initialization is currently tested in a later stage in
> the function for no reason.
> In addition, the test '!comp' will never fail since comp is
> set with the '&' operator. Instead, test if a comp was not
> initialized by testing "!comp->dev".

Applied to mediatek-drm-next [1], thanks.

[1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/=
log/?h=3Dmediatek-drm-next

Regards,
Chun-Kuang.

>
> Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c b/drivers/gpu/drm/me=
diatek/mtk_drm_crtc.c
> index 474efb844249..06f40e589922 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -755,14 +755,22 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
>         for (i =3D 0; i < path_len; i++) {
>                 enum mtk_ddp_comp_id comp_id =3D path[i];
>                 struct device_node *node;
> +               struct mtk_ddp_comp *comp;
>
>                 node =3D priv->comp_node[comp_id];
> +               comp =3D &priv->ddp_comp[comp_id];
> +
>                 if (!node) {
>                         dev_info(dev,
>                                  "Not creating crtc %d because component =
%d is disabled or missing\n",
>                                  pipe, comp_id);
>                         return 0;
>                 }
> +
> +               if (!comp->dev) {
> +                       dev_err(dev, "Component %pOF not initialized\n", =
node);
> +                       return -ENODEV;
> +               }
>         }
>
>         mtk_crtc =3D devm_kzalloc(dev, sizeof(*mtk_crtc), GFP_KERNEL);
> @@ -787,16 +795,8 @@ int mtk_drm_crtc_create(struct drm_device *drm_dev,
>         for (i =3D 0; i < mtk_crtc->ddp_comp_nr; i++) {
>                 enum mtk_ddp_comp_id comp_id =3D path[i];
>                 struct mtk_ddp_comp *comp;
> -               struct device_node *node;
>
> -               node =3D priv->comp_node[comp_id];
>                 comp =3D &priv->ddp_comp[comp_id];
> -               if (!comp) {
> -                       dev_err(dev, "Component %pOF not initialized\n", =
node);
> -                       ret =3D -ENODEV;
> -                       return ret;
> -               }
> -
>                 mtk_crtc->ddp_comp[i] =3D comp;
>
>                 if (comp->funcs) {
> --
> 2.17.1
>