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Date:   Mon, 6 Jun 2022 21:25:11 +0200
From:   Sam Ravnborg <sam@ravnborg.org>
To:     Hsin-Yi Wang <hsinyi@chromium.org>
Cc:     Chun-Kuang Hu <chunkuang.hu@kernel.org>,
        Hans de Goede <hdegoede@redhat.com>,
        Thierry Reding <thierry.reding@gmail.com>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        dri-devel@lists.freedesktop.org,
        linux-mediatek@lists.infradead.org,
        Rob Clark <robdclark@chromium.org>,
        Stephen Boyd <swboyd@chromium.org>,
        Douglas Anderson <dianders@chromium.org>,
        Rob Herring <robh+dt@kernel.org>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 5/8] drm/panel: panel-simple: Implement
 .get_orientation callback
Message-ID: <Yp5Ul/ODUB/sQ0Jf@ravnborg.org>
References: <20220606152431.1889185-1-hsinyi@chromium.org>
 <20220606152431.1889185-6-hsinyi@chromium.org>
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In-Reply-To: <20220606152431.1889185-6-hsinyi@chromium.org>
Precedence: bulk

Hi Hsin-Yi,

On Mon, Jun 06, 2022 at 11:24:28PM +0800, Hsin-Yi Wang wrote:
> To return the orientation property to drm/kms driver.
> 
> Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
> Reviewed-by: Hans de Goede <hdegoede@redhat.com>
> Reviewed-by: Douglas Anderson <dianders@chromium.org>
> ---
>  drivers/gpu/drm/panel/panel-simple.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
> index 4a2e580a2f7b..f232b8cf4075 100644
> --- a/drivers/gpu/drm/panel/panel-simple.c
> +++ b/drivers/gpu/drm/panel/panel-simple.c
> @@ -411,7 +411,12 @@ static int panel_simple_get_modes(struct drm_panel *panel,
>  	/* add hard-coded panel modes */
>  	num += panel_simple_get_non_edid_modes(p, connector);
>  
> -	/* set up connector's "panel orientation" property */
> +	/*
> +	 * drm drivers are expected to call drm_panel_get_orientation() to get
> +	 * panel's orientation then drm_connector_set_panel_orientation() to
> +	 * set the property before drm_dev_register(). Otherwise there will be
> +	 * a WARN_ON if orientation is set after drm is registered.
> +	 */

This comment is not really relevant here. If we need to explain this
then put it in drm_panel.c/h - as this applies for all panels and not
just the panel_simple.
Keep in mind, this is the source new panels often use a inspiration and
no need to have this copied around.

>  	drm_connector_set_panel_orientation(connector, p->orientation);
>  
>  	return num;
> @@ -434,6 +439,14 @@ static int panel_simple_get_timings(struct drm_panel *panel,
>  	return p->desc->num_timings;
>  }
>  
> +static enum drm_panel_orientation panel_simple_get_orientation(struct drm_panel *panel)
> +{
> +       struct panel_simple *p = to_panel_simple(panel);
> +
> +       return p->orientation;
> +}
> +
> +
>  static const struct drm_panel_funcs panel_simple_funcs = {
>  	.disable = panel_simple_disable,
>  	.unprepare = panel_simple_unprepare,
> @@ -441,6 +454,7 @@ static const struct drm_panel_funcs panel_simple_funcs = {
>  	.enable = panel_simple_enable,
>  	.get_modes = panel_simple_get_modes,
>  	.get_timings = panel_simple_get_timings,
> +	.get_orientation = panel_simple_get_orientation,

I like the order in this list to match the order in the .h file.
So my OCD would like you to move it up right after get_modes,
but feel free to ignore this.

With the suggested changes:
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>

>  };
>  
>  static struct panel_desc panel_dpi;
> -- 
> 2.36.1.255.ge46751e96f-goog