Re: [PATCH 3/3] drm/bridge: add TH1520 DesignWare MIPI DSI host controller

Re: [PATCH 3/3] drm/bridge: add TH1520 DesignWare MIPI DSI host controller

[kernel test robot]

Hi Icenowy,

kernel test robot noticed the following build warnings:

[auto build test WARNING on c03c1a14507dfaf8b856c2608f9ac216021fc222]

url:    https://github.com/intel-lab-lkp/linux/commits/Icenowy-Zheng/dt-bindings-display-bridge-document-TH1520-MIPI-DSI-controller/20261030-154749
base:   c03c1a14507dfaf8b856c2608f9ac216021fc222
patch link:    https://lore.kernel.org/r/20261030-th1520-dw-mipi-dsi-v1-3-753f34fd304f%40iscas.ac.cn
patch subject: [PATCH 3/3] drm/bridge: add TH1520 DesignWare MIPI DSI host controller
config: arm64-randconfig-1001-20261031 (https://download.01.org/0day-ci/archive/20261031/202610311004.6oZFiXBi-lkp@intel.com/config)
compiler: clang version 24.0.0git (https://github.com/llvm/llvm-project c2ea4440d4b64c148de4fdfca1fc2c437a0701e4)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20261031/202610311004.6oZFiXBi-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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202610311004.6oZFiXBi-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/bridge/th1520-dw-mipi-dsi.c:445:22: warning: variable 'ret' is uninitialized when used here [-Wuninitialized]
     445 |                 dev_err_probe(dev, ret, "Unable to get DSI registers\n");
         |                                    ^~~
   drivers/gpu/drm/bridge/th1520-dw-mipi-dsi.c:428:12: note: initialize the variable 'ret' to silence this warning
     428 |         int i, ret;
         |                   ^
         |                    = 0
   1 warning generated.


vim +/ret +445 drivers/gpu/drm/bridge/th1520-dw-mipi-dsi.c

   420	
   421	static int th1520_dw_mipi_dsi_probe(struct platform_device *pdev)
   422	{
   423		const struct dsi_chip_data *cdata;
   424		struct device *dev = &pdev->dev;
   425		struct th1520_dw_mipi_dsi *dsi;
   426		struct resource *res;
   427		void __iomem *base;
   428		int i, ret;
   429	
   430		dsi = devm_kzalloc(dev, sizeof(*dsi), GFP_KERNEL);
   431		if (!dsi)
   432			return -ENOMEM;
   433	
   434		dsi->dev = dev;
   435	
   436		dsi->syscon = syscon_regmap_lookup_by_phandle(dev->of_node, "syscon");
   437		if (IS_ERR(dsi->syscon)) {
   438			ret = PTR_ERR(dsi->syscon);
   439			dev_err_probe(dev, ret, "Unable to get system controller regmap\n");
   440			return ret;
   441		}
   442	
   443		base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
   444		if (IS_ERR(base)) {
 > 445			dev_err_probe(dev, ret, "Unable to get DSI registers\n");
   446			return PTR_ERR(base);
   447		}
   448	
   449		cdata = of_device_get_match_data(dev);
   450		i = 0;
   451		while (cdata[i].reg) {
   452			if (cdata[i].reg == res->start) {
   453				dsi->cdata = &cdata[i];
   454				break;
   455			}
   456	
   457			i++;
   458		}
   459	
   460		if (!dsi->cdata) {
   461			dev_err(dev, "Failed to find chip data for this controller\n");
   462			return -EINVAL;
   463		}
   464	
   465		dsi->clk_ref = devm_clk_get_enabled(dev, "ref");
   466		if (IS_ERR(dsi->clk_ref)) {
   467			ret = PTR_ERR(dsi->clk_ref);
   468			dev_err_probe(dev, ret, "Unable to get PHY reference clock\n");
   469			return ret;
   470		}
   471	
   472		dsi->clk_cfg = devm_clk_get_enabled(dev, "phy_cfg");
   473		if (IS_ERR(dsi->clk_cfg)) {
   474			ret = PTR_ERR(dsi->clk_cfg);
   475			dev_err_probe(dev, ret, "Unable to get PHY configuration clock\n");
   476			return ret;
   477		}
   478	
   479		dsi->clk_pix = devm_clk_get(dev, "pixel");
   480		if (IS_ERR(dsi->clk_pix)) {
   481			ret = PTR_ERR(dsi->clk_pix);
   482			dev_err_probe(dev, ret, "Unable to get PHY pixel clock\n");
   483			return ret;
   484		}
   485	
   486		dsi->pdata.base = base;
   487		dsi->pdata.priv_data = dsi;
   488		dsi->pdata.max_data_lanes = 4;
   489		dsi->pdata.phy_ops = &th1520_dw_mipi_dsi_phy_ops;
   490		dsi->pdata.mode_valid = dsi_mode_valid;
   491	
   492		platform_set_drvdata(pdev, dsi);
   493	
   494		dsi->dmd = dw_mipi_dsi_probe(pdev, &dsi->pdata);
   495		if (IS_ERR(dsi->dmd)) {
   496			ret = PTR_ERR(dsi->dmd);
   497			dev_err_probe(dev, ret, "Failed to initialize mipi dsi host\n");
   498			return ret;
   499		}
   500	
   501		return 0;
   502	}
   503	

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