Re: [PATCH v2 7/7] drm/atmel-hlcdc: Replace the panel usage with drm_panel_bridge.

[Archit Taneja]

On 06/06/2017 02:27 PM, Boris Brezillon wrote:
> Hi Archit,
>
> On Mon, 5 Jun 2017 21:06:20 +0530
> Archit Taneja <architt@xxxxxxxxxxxxxx> wrote:
>
> > Hi,
> >
> > When pushing to drm-misc-next, I got a minor merge conflict when dim tried
> > to rebuild drm-tip.
> >
> > The reason for the conflict was because the following commit was present
> > in drm-tip but not in drm-misc:
> >
> > https://cgit.freedesktop.org/drm-tip/commit/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_output.c?id=6bee9b78a7a5ea257b24d93974538938c82b1169
> >
> > I fixed the conflict such that drm-tip is rebuit successfully. I'd
> > however like if Eric and Boris could have a look at atmel_hlcdc_output.c
> > to check if things are okay.
>
> Where can I find the fix you made to fix this problem?

+Sean, I missed adding him in the original message.

The fix is a part of the commit that merged drm-misc-next into drm-tip:

https://cgit.freedesktop.org/drm-tip/commit/?id=62a258c9c517c7c97bc4545f77af21ee03e23e1a

The commit "drm/atmel-hlcdc: Fix output initialization" was a part of 4.12-rc2.
drm-misc-next is still based off 4.12-rc1, so this commit wasn't present.

Sean will observe some minor merge conflicts when he rebases drm-misc-next onto
a more recent tag from Linus.

Thanks,
Archit

> [...]
>
> > >  	if (panel) {
> > > -		output->connector.dpms = DRM_MODE_DPMS_OFF;
> > > -		output->connector.polled = DRM_CONNECTOR_POLL_CONNECT;
> > > -		drm_connector_helper_add(&output->connector,
> > > -				&atmel_hlcdc_panel_connector_helper_funcs);
> > > -		ret = drm_connector_init(dev, &output->connector,
> > > -					 &atmel_hlcdc_panel_connector_funcs,
> > > -					 DRM_MODE_CONNECTOR_Unknown);
> > > -		if (ret)
> > > -			goto err_encoder_cleanup;
> > > -
> > > -		drm_mode_connector_attach_encoder(&output->connector,
> > > -						  &output->encoder);
> > > -
> > > -		ret = drm_panel_attach(panel, &output->connector);
> > > -		if (ret) {
> > > -			drm_connector_cleanup(&output->connector);
> > > -			goto err_encoder_cleanup;
> > > -		}
> > > -
> > > -		output->panel = panel;
> > > +		bridge = drm_panel_bridge_add(panel, DRM_MODE_CONNECTOR_Unknown);
> > > +		if (IS_ERR(bridge))
> > > +			return PTR_ERR(bridge);
> > >
> > >  		return 0;
>
> Just noticed that this is wrong. We should not return here, otherwise
> the panel bridge is never attached to the encoder.
>
> > >  	}
> > >
> > >  	if (bridge) {
> > > -		ret = drm_bridge_attach(&output->encoder, bridge, NULL);
> > > +		ret = drm_bridge_attach(encoder, bridge, NULL);
> > >  		if (!ret)
> > >  			return 0;
> > > +
> > > +		if (panel)
> > > +			drm_panel_bridge_remove(bridge);
> > >  	}
> > >
> > > -err_encoder_cleanup:
> > > -	drm_encoder_cleanup(&output->encoder);
> > > +	drm_encoder_cleanup(encoder);
> > >
> > >  	return ret;
> > >  }

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