Hi Thomas,

I love your patch! Yet something to improve:

[auto build test ERROR on next-20200305]
[also build test ERROR on v5.6-rc4]
[cannot apply to rockchip/for-next shawnguo/for-next sunxi/sunxi/for-next tegra/for-next linus/master v5.6-rc4 v5.6-rc3 v5.6-rc2]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Thomas-Zimmermann/drm-Convert-drivers-to-drm_simple_encoder_init/20200306-045931
base:    47466dcf84ee66a973ea7d2fca7e582fe9328932
config: arm-at91_dt_defconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (GCC) 7.5.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.5.0 make.cross ARCH=arm 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   drivers/gpu//drm/atmel-hlcdc/atmel_hlcdc_output.c: In function 'atmel_hlcdc_attach_endpoint':
>> drivers/gpu//drm/atmel-hlcdc/atmel_hlcdc_output.c:98:8: error: implicit declaration of function 'drm_simple_encoder_init'; did you mean 'drm_encoder_init'? [-Werror=implicit-function-declaration]
     ret = drm_simple_encoder_init(dev, &output->encoder,
           ^~~~~~~~~~~~~~~~~~~~~~~
           drm_encoder_init
   cc1: some warnings being treated as errors

vim +98 drivers/gpu//drm/atmel-hlcdc/atmel_hlcdc_output.c

    65	
    66	static int atmel_hlcdc_attach_endpoint(struct drm_device *dev, int endpoint)
    67	{
    68		struct atmel_hlcdc_rgb_output *output;
    69		struct device_node *ep;
    70		struct drm_panel *panel;
    71		struct drm_bridge *bridge;
    72		int ret;
    73	
    74		ep = of_graph_get_endpoint_by_regs(dev->dev->of_node, 0, endpoint);
    75		if (!ep)
    76			return -ENODEV;
    77	
    78		ret = drm_of_find_panel_or_bridge(dev->dev->of_node, 0, endpoint,
    79						  &panel, &bridge);
    80		if (ret) {
    81			of_node_put(ep);
    82			return ret;
    83		}
    84	
    85		output = devm_kzalloc(dev->dev, sizeof(*output), GFP_KERNEL);
    86		if (!output) {
    87			of_node_put(ep);
    88			return -ENOMEM;
    89		}
    90	
    91		output->bus_fmt = atmel_hlcdc_of_bus_fmt(ep);
    92		of_node_put(ep);
    93		if (output->bus_fmt < 0) {
    94			dev_err(dev->dev, "endpoint %d: invalid bus width\n", endpoint);
    95			return -EINVAL;
    96		}
    97	
  > 98		ret = drm_simple_encoder_init(dev, &output->encoder,
    99					      DRM_MODE_ENCODER_NONE);
   100		if (ret)
   101			return ret;
   102	
   103		output->encoder.possible_crtcs = 0x1;
   104	
   105		if (panel) {
   106			bridge = drm_panel_bridge_add_typed(panel,
   107							    DRM_MODE_CONNECTOR_Unknown);
   108			if (IS_ERR(bridge))
   109				return PTR_ERR(bridge);
   110		}
   111	
   112		if (bridge) {
   113			ret = drm_bridge_attach(&output->encoder, bridge, NULL, 0);
   114			if (!ret)
   115				return 0;
   116	
   117			if (panel)
   118				drm_panel_bridge_remove(bridge);
   119		}
   120	
   121		drm_encoder_cleanup(&output->encoder);
   122	
   123		return ret;
   124	}
   125	

---
0-DAY CI Kernel Test Service, Intel Corporation
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