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

[Archit Taneja <architt@codeaurora.org>]

On 06/06/2017 02:27 PM, Boris Brezillon wrote:
> Hi Archit,
>
> On Mon, 5 Jun 2017 21:06:20 +0530
> Archit Taneja <architt@codeaurora.org> 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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