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From:   Mark Yacoub <markyacoub@chromium.org>
Date:   Wed, 15 Dec 2021 12:25:02 -0500
Message-ID: <CAJUqKUrCibOCjPca_YaLpF2_zsb-85CbKbrs9KyGqWwGrWOGyg@mail.gmail.com>
Subject: Re: [PATCH] mediatek: Set default value for Panel Orientation
 connector prop.
To:     Chun-Kuang Hu <chunkuang.hu@kernel.org>
Cc:     Sean Paul <sean@poorly.run>,
        "moderated list:ARM/Mediatek SoC support" 
        <linux-mediatek@lists.infradead.org>,
        Sean Paul <seanpaul@chromium.org>,
        Mark Yacoub <markyacoub@google.com>,
        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>
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On Wed, Dec 15, 2021 at 11:14 AM Chun-Kuang Hu <chunkuang.hu@kernel.org> wr=
ote:
>
> Hi, Mark:
>
> Mark Yacoub <markyacoub@chromium.org> =E6=96=BC 2021=E5=B9=B412=E6=9C=881=
4=E6=97=A5 =E9=80=B1=E4=BA=8C =E4=B8=8B=E5=8D=8811:13=E5=AF=AB=E9=81=93=EF=
=BC=9A
> >
> > Hey CK, can we have this merged?
> > Thank you!
> >
> > On Mon, Oct 25, 2021 at 9:13 PM Sean Paul <sean@poorly.run> wrote:
> > >
> > > On Fri, Oct 22, 2021 at 01:24:03PM -0400, Mark Yacoub wrote:
> > > > From: Mark Yacoub <markyacoub@chromium.org>
> > > >
> > > > [Why]
> > > > Creating the prop uses UNKNOWN as the initial value, which is not a
> > > > supported value if the props is to be supported.
> > > >
> > > > [How]
> > > > Set the panel orientation default value to NORMAL right after creat=
ing
> > > > the prop.
> > >
> > > Reviewed-by: Sean Paul <seanpaul@chromium.org>
> > >
> > > >
> > > > Tested on Jacuzzi(MTK)
> > > > Fixes IGT@kms_properties@get_properties-sanity-{atomic,non-atomic}
> > > >
> > > > Signed-off-by: Mark Yacoub <markyacoub@chromium.org>
> > > > ---
> > > >  drivers/gpu/drm/mediatek/mtk_dsi.c | 2 ++
> > > >  1 file changed, 2 insertions(+)
> > > >
> > > > diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/m=
ediatek/mtk_dsi.c
> > > > index 0ad7157660afa..b7c2528a8f41c 100644
> > > > --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> > > > +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> > > > @@ -1039,6 +1039,8 @@ static int mtk_dsi_encoder_init(struct drm_de=
vice *drm, struct mtk_dsi *dsi)
> > > >               DRM_ERROR("Unable to init panel orientation\n");
> > > >               goto err_cleanup_encoder;
> > > >       }
> > > > +     drm_connector_set_panel_orientation(dsi->connector,
> > > > +                                         DRM_MODE_PANEL_ORIENTATIO=
N_NORMAL);
>
> In drm_connector_set_panel_orientation() [1], I find that the
> orientation could be set only once. Once you set it to normal, it
> could not be set to other orientation. Right?
>
Hello,
Yeah this looks true, and makes sense according to the documentation:
https://01.org/linuxgraphics/gfx-docs/drm/gpu/drm-kms.html#:~:text=3Done%20=
standardized%20property%3A-,panel%20orientation%3A,-On%20some%20devices

Panel orientation has to do with the how the hardware is mounted, in
contrast with the Rotation property. All the HW we have right now has
a normal panel orientation so it makes sense to be set this way. Among
other drivers, panel orientation is always set right after the
property is initialized.

> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tr=
ee/drivers/gpu/drm/drm_connector.c?h=3Dv5.16-rc5#n2302
>
> Regards,
> Chun-Kuang.
>
> > > >
> > > >       drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
> > > >
> > > > --
> > > > 2.33.0.1079.g6e70778dc9-goog
> > > >
> > >
> > > --
> > > Sean Paul, Software Engineer, Google / Chromium OS