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Date:   Sat, 18 Jan 2020 14:04:18 +0100
From:   Sam Ravnborg <sam@ravnborg.org>
To:     Oleksandr Suvorov <oleksandr.suvorov@toradex.com>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Igor Opanyuk <igor.opanyuk@toradex.com>,
        Marcel Ziswiler <marcel.ziswiler@toradex.com>,
        Stefan Agner <stefan@agner.ch>,
        Daniel Vetter <daniel@ffwll.ch>,
        David Airlie <airlied@linux.ie>,
        Thierry Reding <thierry.reding@gmail.com>,
        "dri-devel@lists.freedesktop.org" <dri-devel@lists.freedesktop.org>
Subject: Re: [PATCH 1/3] drm/panel: make LVDS panel driver DPI capable
Message-ID: <20200118130418.GA13417@ravnborg.org>
References: <20200115123401.2264293-1-oleksandr.suvorov@toradex.com>
 <20200115123401.2264293-2-oleksandr.suvorov@toradex.com>
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Hi Oleksandr & Stafan.

Thanks for the update to panel-lvds.


On Wed, Jan 15, 2020 at 12:34:17PM +0000, Oleksandr Suvorov wrote:
> From: Stefan Agner <stefan@agner.ch>
> 
> The LVDS panel driver has almost everything which is required to
> describe a simple parallel RGB panel (also known as DPI, Display
> Pixel Interface).
> 
> Signed-off-by: Stefan Agner <stefan@agner.ch>
> Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>
> ---

There are a few high-level things we need to have sorted out.

The driver, when this patch is added, assumes that certain properties
are now mandatory when using the panel-dpi compatible.
  - data-mapping
  - width-mm
  - height-mm
  - panel-timing

But this does not match the panel-dpi binding.
So we need the panel-dpi binding updated first.


The current driver specify the connector type in drm_panel_init().
But a DPI panel is assumed to use a DRM_MODE_CONNECTOR_DPI,
and not a DRM_MODE_CONNECTOR_LVDS.
So the drm_panel_init() call needs to take into account the type
of binding.


> @@ -257,7 +279,7 @@ static struct platform_driver panel_lvds_driver = {
>  	.probe		= panel_lvds_probe,
>  	.remove		= panel_lvds_remove,
>  	.driver		= {
> -		.name	= "panel-lvds",
> +		.name	= "panel-generic",

I think changing the name of the driver like this is an UAPI change,
which is not OK

>  		.of_match_table = panel_lvds_of_table,
>  	},
>  };

	Sam