Hi "Christian, I love your patch! Perhaps something to improve: [auto build test WARNING on drm-intel/for-linux-next] [also build test WARNING on drm-exynos/exynos-drm-next tegra-drm/drm/tegra/for-next linus/master v5.13-rc6 next-20210616] [cannot apply to drm-tip/drm-tip drm/drm-next] [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/dma-buf-some-dma... base: git://anongit.freedesktop.org/drm-intel for-linux-next config: i386-randconfig-s001-20210615 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce: # apt-get install sparse # sparse version: v0.6.3-341-g8af24329-dirty # https://github.com/0day-ci/linux/commit/058b99a2929f84c7f2cb1516dcc8674bf... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Christian-K-nig/dma-buf-some-dma_fence_chain-improvements/20210616-182806 git checkout 058b99a2929f84c7f2cb1516dcc8674bf3f2a661 # save the attached .config to linux build tree make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=i386 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; sparse warnings: (new ones prefixed by >>) drivers/dma-buf/dma-fence-chain.c:28:15: sparse: expected struct dma_fence_chain **__ret drivers/dma-buf/dma-fence-chain.c:28:15: sparse: got struct dma_fence_chain [noderef] __rcu ** drivers/dma-buf/dma-fence-chain.c:28:13: sparse: sparse: incorrect type in assignment (different address spaces) @@ expected struct dma_fence_chain [noderef] __rcu **tmp @@ got struct dma_fence_chain **[assigned] __ret @@ drivers/dma-buf/dma-fence-chain.c:28:13: sparse: expected struct dma_fence_chain [noderef] __rcu **tmp drivers/dma-buf/dma-fence-chain.c:28:13: sparse: got struct dma_fence_chain **[assigned] __ret vim +28 drivers/dma-buf/dma-fence-chain.c 16 17 /** 18 * dma_fence_chain_enqueue - enqeue a chain node for garbage collection 19 * @chain: the chain node to enqueue 20 * 21 * Add the chain node to the end of the gc fifo. 22 */ 23 static void dma_fence_chain_enqueue(struct dma_fence_chain *chain) 24 { 25 struct dma_fence_chain __rcu **tmp; 26 27 RCU_INIT_POINTER(chain->next, NULL); 29 &chain->next); 30 31 /* This is intentionally unordered since we only need the fifo for gc */ 32 rcu_assign_pointer(*tmp, chain); 33 } 34 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org