Hi Thomas, I love your patch! Yet something to improve: [auto build test ERROR on next-20200305] [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 v5.6-rc4] [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: mips-randconfig-a001-20200306 (attached as .config) compiler: mipsel-linux-gcc (GCC) 5.5.0 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=5.5.0 make.cross ARCH=mips If you fix the issue, kindly add following tag Reported-by: kbuild test robot All errors (new ones prefixed by >>): drivers/gpu/drm/drm_writeback.c: In function 'drm_writeback_connector_init': >> drivers/gpu/drm/drm_writeback.c:191:8: error: implicit declaration of function 'drm_simple_encoder_init' [-Werror=implicit-function-declaration] ret = drm_simple_encoder_init(dev, &wb_connector->encoder, ^ cc1: some warnings being treated as errors vim +/drm_simple_encoder_init +191 drivers/gpu/drm/drm_writeback.c 149 150 /** 151 * drm_writeback_connector_init - Initialize a writeback connector and its properties 152 * @dev: DRM device 153 * @wb_connector: Writeback connector to initialize 154 * @con_funcs: Connector funcs vtable 155 * @enc_helper_funcs: Encoder helper funcs vtable to be used by the internal encoder 156 * @formats: Array of supported pixel formats for the writeback engine 157 * @n_formats: Length of the formats array 158 * 159 * This function creates the writeback-connector-specific properties if they 160 * have not been already created, initializes the connector as 161 * type DRM_MODE_CONNECTOR_WRITEBACK, and correctly initializes the property 162 * values. It will also create an internal encoder associated with the 163 * drm_writeback_connector and set it to use the @enc_helper_funcs vtable for 164 * the encoder helper. 165 * 166 * Drivers should always use this function instead of drm_connector_init() to 167 * set up writeback connectors. 168 * 169 * Returns: 0 on success, or a negative error code 170 */ 171 int drm_writeback_connector_init(struct drm_device *dev, 172 struct drm_writeback_connector *wb_connector, 173 const struct drm_connector_funcs *con_funcs, 174 const struct drm_encoder_helper_funcs *enc_helper_funcs, 175 const u32 *formats, int n_formats) 176 { 177 struct drm_property_blob *blob; 178 struct drm_connector *connector = &wb_connector->base; 179 struct drm_mode_config *config = &dev->mode_config; 180 int ret = create_writeback_properties(dev); 181 182 if (ret != 0) 183 return ret; 184 185 blob = drm_property_create_blob(dev, n_formats * sizeof(*formats), 186 formats); 187 if (IS_ERR(blob)) 188 return PTR_ERR(blob); 189 190 drm_encoder_helper_add(&wb_connector->encoder, enc_helper_funcs); > 191 ret = drm_simple_encoder_init(dev, &wb_connector->encoder, 192 DRM_MODE_ENCODER_VIRTUAL); 193 if (ret) 194 goto fail; 195 196 connector->interlace_allowed = 0; 197 198 ret = drm_connector_init(dev, connector, con_funcs, 199 DRM_MODE_CONNECTOR_WRITEBACK); 200 if (ret) 201 goto connector_fail; 202 203 ret = drm_connector_attach_encoder(connector, 204 &wb_connector->encoder); 205 if (ret) 206 goto attach_fail; 207 208 INIT_LIST_HEAD(&wb_connector->job_queue); 209 spin_lock_init(&wb_connector->job_lock); 210 211 wb_connector->fence_context = dma_fence_context_alloc(1); 212 spin_lock_init(&wb_connector->fence_lock); 213 snprintf(wb_connector->timeline_name, 214 sizeof(wb_connector->timeline_name), 215 "CONNECTOR:%d-%s", connector->base.id, connector->name); 216 217 drm_object_attach_property(&connector->base, 218 config->writeback_out_fence_ptr_property, 0); 219 220 drm_object_attach_property(&connector->base, 221 config->writeback_fb_id_property, 0); 222 223 drm_object_attach_property(&connector->base, 224 config->writeback_pixel_formats_property, 225 blob->base.id); 226 wb_connector->pixel_formats_blob_ptr = blob; 227 228 return 0; 229 230 attach_fail: 231 drm_connector_cleanup(connector); 232 connector_fail: 233 drm_encoder_cleanup(&wb_connector->encoder); 234 fail: 235 drm_property_blob_put(blob); 236 return ret; 237 } 238 EXPORT_SYMBOL(drm_writeback_connector_init); 239 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org