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From:   Chun-Kuang Hu <chunkuang.hu@kernel.org>
Date:   Sun, 2 Aug 2020 11:07:41 +0800
Message-ID: <CAAOTY_99VEs2aNAoWBJhcCMsem5ewmV18B=GMLc_n-Wico_+Hg@mail.gmail.com>
Subject: Re: [PATCH v2 4/5] drm/mediatek: dpi/dsi: change the getting
 possible_crtc way
To:     Frank Wunderlich <frank-w@public-files.de>
Cc:     "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>,
        Chun-Kuang Hu <chunkuang.hu@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        DRI Development <dri-devel@lists.freedesktop.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Jitao Shi <jitao.shi@mediatek.com>
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Sender: linux-kernel-owner@vger.kernel.org
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Hi, Frank:

Frank Wunderlich <frank-w@public-files.de> =E6=96=BC 2020=E5=B9=B47=E6=9C=
=8828=E6=97=A5 =E9=80=B1=E4=BA=8C =E4=B8=8B=E5=8D=887:18=E5=AF=AB=E9=81=93=
=EF=BC=9A

>
> From: Jitao Shi <jitao.shi@mediatek.com>
>
> [Detail]
> dpi/dsi get the possible_crtc by
> mtk_drm_find_possible_crtc_by_comp(*drm_dev, ddp_comp)
>

I would like more information of why do this patch. For example:

For current mediatek dsi encoder, its possible crtc is fixed in crtc
0, and mediatek dpi encoder's possible crtc is fixed in crtc 1. In
some SoC the possible crtc is not fixed in this case, so call
mtk_drm_find_possible_crtc_by_comp() to find out the correct possible
crtc.

Regards,
Chun-Kuang.

> Test: build pass and boot to logo
>
> Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_dpi.c | 3 ++-
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 3 ++-
>  2 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dpi.c b/drivers/gpu/drm/mediate=
k/mtk_dpi.c
> index d4f0fb7ad312..e43977015843 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dpi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dpi.c
> @@ -608,7 +608,8 @@ static int mtk_dpi_bind(struct device *dev, struct de=
vice *master, void *data)
>         drm_encoder_helper_add(&dpi->encoder, &mtk_dpi_encoder_helper_fun=
cs);
>
>         /* Currently DPI0 is fixed to be driven by OVL1 */
> -       dpi->encoder.possible_crtcs =3D BIT(1);
> +       dpi->encoder.possible_crtcs =3D
> +               mtk_drm_find_possible_crtc_by_comp(drm_dev, dpi->ddp_comp=
);
>
>         ret =3D drm_bridge_attach(&dpi->encoder, dpi->bridge, NULL, 0);
>         if (ret) {
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediate=
k/mtk_dsi.c
> index 270bf22c98fe..c31d9c12d4a9 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -892,7 +892,8 @@ static int mtk_dsi_create_conn_enc(struct drm_device =
*drm, struct mtk_dsi *dsi)
>          * Currently display data paths are statically assigned to a crtc=
 each.
>          * crtc 0 is OVL0 -> COLOR0 -> AAL -> OD -> RDMA0 -> UFOE -> DSI0
>          */
> -       dsi->encoder.possible_crtcs =3D 1;
> +       dsi->encoder.possible_crtcs =3D
> +               mtk_drm_find_possible_crtc_by_comp(drm, dsi->ddp_comp);
>
>         /* If there's a bridge, attach to it and let it create the connec=
tor */
>         if (dsi->bridge) {
> --
> 2.25.1
>