[PATCH 4/4] drm/mgag200: Use DMA to copy the framebuffer to the VRAM

[kernel test robot]

Hi Jocelyn,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 457391b0380335d5e9a5babdec90ac53928b23b4]

url:    https://github.com/intel-lab-lkp/linux/commits/Jocelyn-Falempe/drm-mgag200-Rename-constant-MGAREG_Status-to-MGAREG_STATUS/20230505-204705
base:   457391b0380335d5e9a5babdec90ac53928b23b4
patch link:    https://lore.kernel.org/r/20230505124337.854845-5-jfalempe%40redhat.com
patch subject: [PATCH 4/4] drm/mgag200: Use DMA to copy the framebuffer to the VRAM
config: x86_64-randconfig-a001-20230501 (https://download.01.org/0day-ci/archive/20230505/202305052238.7oFMzU5Q-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/intel-lab-lkp/linux/commit/b3cab0043427adee56c6f3169cdfa15526dd331c
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Jocelyn-Falempe/drm-mgag200-Rename-constant-MGAREG_Status-to-MGAREG_STATUS/20230505-204705
        git checkout b3cab0043427adee56c6f3169cdfa15526dd331c
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/gpu/drm/mgag200/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp at intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202305052238.7oFMzU5Q-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/gpu/drm/mgag200/mgag200_dma.c: In function 'mgag200_dma_run_cmd':
>> drivers/gpu/drm/mgag200/mgag200_dma.c:86:13: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
      86 |         int ret;
         |             ^~~


vim +/ret +86 drivers/gpu/drm/mgag200/mgag200_dma.c

    81	
    82	void mgag200_dma_run_cmd(struct mga_device *mdev)
    83	{
    84		struct drm_device *dev = &mdev->base;
    85		u32 primend;
  > 86		int ret;
    87	
    88		/* Add a last block to trigger the softrap interrupt */
    89		mgag200_dma_add_block(mdev,
    90				MGAREG_DMAPAD, 0,
    91				MGAREG_DMAPAD, 0,
    92				MGAREG_DMAPAD, 0,
    93				MGAREG_SOFTRAP, 0);
    94	
    95		primend = mdev->cmd_handle + mdev->cmd_idx * sizeof(struct mga_cmd_block);
    96	
    97		// Use primary DMA to send the commands
    98		WREG32(MGAREG_PRIMADDR, (u32) mdev->cmd_handle);
    99		WREG32(MGAREG_PRIMEND, primend);
   100		mdev->dma_in_use = 1;
   101	
   102		ret = wait_event_timeout(mdev->waitq, mdev->dma_in_use == 0, HZ);
   103	
   104		if (mdev->dma_in_use) {
   105			drm_err(dev, "DMA transfert timed out\n");
   106			/* something goes wrong, reset the DMA engine */
   107			WREG8(MGAREG_OPMODE, MGAOPM_DMA_BLIT);
   108			mdev->dma_in_use = 0;
   109		}
   110	
   111		/* reset command index to start a new sequence */
   112		mdev->cmd_idx = 0;
   113	}
   114	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests