[PATCH] drm/bridge: synopsys: dw-mipi-dsi: fix deferred dsi host probe breaks dsi device probe

[kernel test robot]

Hi Farouk,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-misc/drm-misc-next]
[also build test WARNING on drm/drm-next linus/master v6.7 next-20240112]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Farouk-Bouabid/drm-bridge-synopsys-dw-mipi-dsi-fix-deferred-dsi-host-probe-breaks-dsi-device-probe/20240113-020945
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20240112180737.551318-1-farouk.bouabid%40theobroma-systems.com
patch subject: [PATCH] drm/bridge: synopsys: dw-mipi-dsi: fix deferred dsi host probe breaks dsi device probe
config: i386-buildonly-randconfig-002-20240115 (https://download.01.org/0day-ci/archive/20240116/202401160108.j5Lqkppm-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240116/202401160108.j5Lqkppm-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp at intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202401160108.j5Lqkppm-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c:1187:5: warning: no previous prototype for '__dw_mipi_dsi_probe' [-Wmissing-prototypes]
    1187 | int __dw_mipi_dsi_probe(struct platform_device *pdev,
         |     ^~~~~~~~~~~~~~~~~~~


vim +/__dw_mipi_dsi_probe +1187 drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c

  1186	
> 1187	int __dw_mipi_dsi_probe(struct platform_device *pdev,
  1188			    const struct dw_mipi_dsi_plat_data *plat_data, struct dw_mipi_dsi **dsi_p)
  1189	{
  1190		struct device *dev = &pdev->dev;
  1191		struct reset_control *apb_rst;
  1192		struct dw_mipi_dsi *dsi;
  1193		int ret;
  1194	
  1195		*dsi_p = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
  1196		if (!*dsi_p)
  1197			return -ENOMEM;
  1198	
  1199		dsi = *dsi_p;
  1200	
  1201		dsi->dev = dev;
  1202		dsi->plat_data = plat_data;
  1203	
  1204		if (!plat_data->phy_ops->init || !plat_data->phy_ops->get_lane_mbps ||
  1205		    !plat_data->phy_ops->get_timing) {
  1206			DRM_ERROR("Phy not properly configured\n");
  1207			return -ENODEV;
  1208		}
  1209	
  1210		if (!plat_data->base) {
  1211			dsi->base = devm_platform_ioremap_resource(pdev, 0);
  1212			if (IS_ERR(dsi->base))
  1213				return -ENODEV;
  1214	
  1215		} else {
  1216			dsi->base = plat_data->base;
  1217		}
  1218	
  1219		dsi->pclk = devm_clk_get(dev, "pclk");
  1220		if (IS_ERR(dsi->pclk)) {
  1221			ret = PTR_ERR(dsi->pclk);
  1222			dev_err(dev, "Unable to get pclk: %d\n", ret);
  1223			return ret;
  1224		}
  1225	
  1226		/*
  1227		 * Note that the reset was not defined in the initial device tree, so
  1228		 * we have to be prepared for it not being found.
  1229		 */
  1230		apb_rst = devm_reset_control_get_optional_exclusive(dev, "apb");
  1231		if (IS_ERR(apb_rst)) {
  1232			ret = PTR_ERR(apb_rst);
  1233	
  1234			if (ret != -EPROBE_DEFER)
  1235				dev_err(dev, "Unable to get reset control: %d\n", ret);
  1236	
  1237			return ret;
  1238		}
  1239	
  1240		if (apb_rst) {
  1241			ret = clk_prepare_enable(dsi->pclk);
  1242			if (ret) {
  1243				dev_err(dev, "%s: Failed to enable pclk\n", __func__);
  1244				return ret;
  1245			}
  1246	
  1247			reset_control_assert(apb_rst);
  1248			usleep_range(10, 20);
  1249			reset_control_deassert(apb_rst);
  1250	
  1251			clk_disable_unprepare(dsi->pclk);
  1252		}
  1253	
  1254		dw_mipi_dsi_debugfs_init(dsi);
  1255		pm_runtime_enable(dev);
  1256	
  1257		dsi->dsi_host.ops = &dw_mipi_dsi_host_ops;
  1258		dsi->dsi_host.dev = dev;
  1259		dsi->bridge.driver_private = dsi;
  1260		dsi->bridge.funcs = &dw_mipi_dsi_bridge_funcs;
  1261		dsi->bridge.of_node = pdev->dev.of_node;
  1262	
  1263		ret = mipi_dsi_host_register(&dsi->dsi_host);
  1264		if (ret) {
  1265			dev_err(dev, "Failed to register MIPI host: %d\n", ret);
  1266			pm_runtime_disable(dev);
  1267			dw_mipi_dsi_debugfs_remove(dsi);
  1268			return ret;
  1269		}
  1270	
  1271	
  1272		return 0;
  1273	}
  1274	

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