Re: [PATCH v9 2/2] drm: add kms driver for loongson display controller

[kernel test robot <lkp@intel.com>]

Hi Sui,

I love your patch! Perhaps something to improve:

[auto build test WARNING on drm-misc/drm-misc-next]
[also build test WARNING on linus/master v6.3-rc4 next-20230329]
[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/Sui-Jingfeng/MAINTAINERS-add-maintainers-for-DRM-LOONGSON-driver/20230329-235338
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20230329155033.1303550-3-15330273260%40189.cn
patch subject: [PATCH v9 2/2] drm: add kms driver for loongson display controller
config: x86_64-allyesconfig (https://download.01.org/0day-ci/archive/20230330/202303301403.lRjtbd5K-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/ed6a57085a2dc87999193a71c28399a56e29097b
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Sui-Jingfeng/MAINTAINERS-add-maintainers-for-DRM-LOONGSON-driver/20230329-235338
        git checkout ed6a57085a2dc87999193a71c28399a56e29097b
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/fpga/ drivers/gpu/drm/loongson/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202303301403.lRjtbd5K-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/loongson/lsdc_drv.c:342:11: warning: variable 'ddev' is uninitialized when used here [-Wuninitialized]
                   drm_err(ddev, "Not known device, the driver need update!\n");
                           ^~~~
   include/drm/drm_print.h:469:16: note: expanded from macro 'drm_err'
           __drm_printk((drm), err,, "*ERROR* " fmt, ##__VA_ARGS__)
                         ^~~
   include/drm/drm_print.h:456:21: note: expanded from macro '__drm_printk'
           dev_##level##type((drm)->dev, "[drm] " fmt, ##__VA_ARGS__)
                              ^~~
   include/linux/dev_printk.h:144:44: note: expanded from macro 'dev_err'
           dev_printk_index_wrap(_dev_err, KERN_ERR, dev, dev_fmt(fmt), ##__VA_ARGS__)
                                                     ^~~
   include/linux/dev_printk.h:110:11: note: expanded from macro 'dev_printk_index_wrap'
                   _p_func(dev, fmt, ##__VA_ARGS__);                       \
                           ^~~
   drivers/gpu/drm/loongson/lsdc_drv.c:326:25: note: initialize the variable 'ddev' to silence this warning
           struct drm_device *ddev;
                                  ^
                                   = NULL
   1 warning generated.


vim +/ddev +342 drivers/gpu/drm/loongson/lsdc_drv.c

   321	
   322	static int lsdc_pci_probe(struct pci_dev *pdev,
   323				  const struct pci_device_id *ent)
   324	{
   325		const struct lsdc_desc *descp;
   326		struct drm_device *ddev;
   327		struct lsdc_device *ldev;
   328		int ret;
   329	
   330		ret = pcim_enable_device(pdev);
   331		if (ret)
   332			return ret;
   333	
   334		pci_set_master(pdev);
   335	
   336		ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
   337		if (ret)
   338			return ret;
   339	
   340		descp = lsdc_detect_chip(pdev, ent);
   341		if (IS_ERR_OR_NULL(descp)) {
 > 342			drm_err(ddev, "Not known device, the driver need update!\n");
   343			return -ENODEV;
   344		}
   345	
   346		dev_info(&pdev->dev, "%s found, revision: %u",
   347			 chip_to_str(descp->chip), pdev->revision);
   348	
   349		ldev = lsdc_create_device(pdev, descp, &lsdc_drm_driver);
   350		if (IS_ERR(ldev))
   351			return PTR_ERR(ldev);
   352	
   353		ddev = &ldev->base;
   354	
   355		pci_set_drvdata(pdev, ddev);
   356	
   357		ret = devm_request_irq(&pdev->dev,
   358				       pdev->irq,
   359				       lsdc_get_irq_handler(descp),
   360				       IRQF_SHARED,
   361				       dev_name(&pdev->dev),
   362				       ddev);
   363		if (ret) {
   364			drm_err(ddev, "Failed to register interrupt: %d\n", ret);
   365			return ret;
   366		}
   367	
   368		ret = drm_dev_register(ddev, 0);
   369		if (ret)
   370			return ret;
   371	
   372		drm_fbdev_generic_setup(ddev, 32);
   373	
   374		return 0;
   375	}
   376	

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https://github.com/intel/lkp-tests