Hi "Christian,

I love your patch! Perhaps something to improve:

[auto build test WARNING on drm-tip/drm-tip]
[cannot apply to drm-intel/for-linux-next drm-exynos/exynos-drm-next tegra-drm/drm/tegra/for-next linus/master drm/drm-next v5.12-rc3 next-20210315]
[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]

url:    https://github.com/0day-ci/linux/commits/Christian-K-nig/drm-ttm-move-swapout-logic-around/20210316-000551
base:   git://anongit.freedesktop.org/drm/drm-tip drm-tip
config: i386-allyesconfig (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/824dca26fe395899b41d9790944ddea345f7a6fd
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Christian-K-nig/drm-ttm-move-swapout-logic-around/20210316-000551
        git checkout 824dca26fe395899b41d9790944ddea345f7a6fd
        # save the attached .config to linux build tree
        make W=1 ARCH=i386 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   drivers/gpu/drm/ttm/ttm_device.c:42: warning: Function parameter or member 'ttm_global_mutex' not described in 'DEFINE_MUTEX'
   drivers/gpu/drm/ttm/ttm_device.c:42: warning: expecting prototype for ttm_global_mutex(). Prototype was for DEFINE_MUTEX() instead
   drivers/gpu/drm/ttm/ttm_device.c:110: warning: Function parameter or member 'ctx' not described in 'ttm_global_swapout'
   drivers/gpu/drm/ttm/ttm_device.c:110: warning: Function parameter or member 'gfp_flags' not described in 'ttm_global_swapout'
>> drivers/gpu/drm/ttm/ttm_device.c:110: warning: expecting prototype for A buffer object shrink method that tries to swap out the first(). Prototype was for ttm_global_swapout() instead


vim +110 drivers/gpu/drm/ttm/ttm_device.c

   104	
   105	/**
   106	 * A buffer object shrink method that tries to swap out the first
   107	 * buffer object on the global::swap_lru list.
   108	 */
   109	long ttm_global_swapout(struct ttm_operation_ctx *ctx, gfp_t gfp_flags)
 > 110	{
   111		struct ttm_global *glob = &ttm_glob;
   112		struct ttm_buffer_object *bo;
   113		unsigned i;
   114		int ret;
   115	
   116		spin_lock(&glob->lru_lock);
   117		for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
   118			list_for_each_entry(bo, &glob->swap_lru[i], swap) {
   119				uint32_t num_pages = bo->ttm->num_pages;
   120	
   121				ret = ttm_bo_swapout(bo, ctx, gfp_flags);
   122				/* ttm_bo_swapout has dropped the lru_lock */
   123				if (!ret)
   124					return num_pages;
   125				if (ret != -EBUSY)
   126					return ret;
   127			}
   128		}
   129		spin_unlock(&glob->lru_lock);
   130		return 0;
   131	}
   132	EXPORT_SYMBOL(ttm_global_swapout);
   133	

---
0-DAY CI Kernel Test Service, Intel Corporation
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