Re: [PATCH] drm: rcar-du: Don't create encoder for unconnected LVDS outputs

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Geert,

On Mon, Aug 23, 2021 at 02:25:32PM +0200, Geert Uytterhoeven wrote:
> On Sun, Aug 22, 2021 at 2:36 AM Laurent Pinchart wrote:
> > On R-Car D3 and E3, the LVDS encoders provide the pixel clock to the DU,
> > even when LVDS outputs are not used. For this reason, the rcar-lvds
> > driver probes successfully on those platforms even if no further bridge
> > or panel is connected to the LVDS output, in order to provide the
> > rcar_lvds_clk_enable() and rcar_lvds_clk_disable() functions to the DU
> > driver.
> >
> > If an LVDS output isn't connected, trying to create a DRM connector for
> > the output will fail. Fix this by skipping connector creation in that
> > case, and also skip creation of the DRM encoder as there's no point in
> > an encoder without a connector.
> >
> > Fixes: e9e056949c92 ("drm: rcar-du: lvds: Convert to DRM panel bridge helper")
> > Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
> 
> Can you please change that to
> Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ?

Sure thing.

> > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> 
> Thanks, the scary warning on Ebisu-4D is gone, so
> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
> 
> Disclaimer: there are no displays connected to my Ebisu-4D.

That's the best way to ensure the absence of display issues. It works
great for camera testing too, if you also remove networking and storage
:-)

-- 
Regards,

Laurent Pinchart