Hi Thomas,

I love your patch! Yet something to improve:

[auto build test ERROR on next-20200914]
[also build test ERROR on v5.9-rc5]
[cannot apply to linuxtv-media/master drm-intel/for-linux-next tegra/for-next linus/master v5.9-rc5 v5.9-rc4 v5.9-rc3]
[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/Thomas-Zimmermann/dma-buf-Flag-vmap-ed-memory-as-system-or-I-O-memory/20200914-192712
base:    f965d3ec86fa89285db0fbb983da76ba9c398efa
config: i386-randconfig-r034-20200913 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce (this is a W=1 build):
        # 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 errors (new ones prefixed by >>):

   In file included from drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c:291:
>> drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c:89:10: error: initialization of 'int (*)(struct dma_buf *, struct dma_buf_map *)' from incompatible pointer type 'void * (*)(struct dma_buf *)' [-Werror=incompatible-pointer-types]
      89 |  .vmap = mock_dmabuf_vmap,
         |          ^~~~~~~~~~~~~~~~
   drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c:89:10: note: (near initialization for 'mock_dmabuf_ops.vmap')
   cc1: some warnings being treated as errors

# https://github.com/0day-ci/linux/commit/b9513704e28f25636f00827154183df60a80d95c
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Thomas-Zimmermann/dma-buf-Flag-vmap-ed-memory-as-system-or-I-O-memory/20200914-192712
git checkout b9513704e28f25636f00827154183df60a80d95c
vim +89 drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c

6cca22ede8a448 drivers/gpu/drm/i915/selftests/mock_dmabuf.c Chris Wilson 2017-02-13  83  
6cca22ede8a448 drivers/gpu/drm/i915/selftests/mock_dmabuf.c Chris Wilson 2017-02-13  84  static const struct dma_buf_ops mock_dmabuf_ops =  {
6cca22ede8a448 drivers/gpu/drm/i915/selftests/mock_dmabuf.c Chris Wilson 2017-02-13  85  	.map_dma_buf = mock_map_dma_buf,
6cca22ede8a448 drivers/gpu/drm/i915/selftests/mock_dmabuf.c Chris Wilson 2017-02-13  86  	.unmap_dma_buf = mock_unmap_dma_buf,
6cca22ede8a448 drivers/gpu/drm/i915/selftests/mock_dmabuf.c Chris Wilson 2017-02-13  87  	.release = mock_dmabuf_release,
6cca22ede8a448 drivers/gpu/drm/i915/selftests/mock_dmabuf.c Chris Wilson 2017-02-13  88  	.mmap = mock_dmabuf_mmap,
6cca22ede8a448 drivers/gpu/drm/i915/selftests/mock_dmabuf.c Chris Wilson 2017-02-13 @89  	.vmap = mock_dmabuf_vmap,
6cca22ede8a448 drivers/gpu/drm/i915/selftests/mock_dmabuf.c Chris Wilson 2017-02-13  90  	.vunmap = mock_dmabuf_vunmap,
6cca22ede8a448 drivers/gpu/drm/i915/selftests/mock_dmabuf.c Chris Wilson 2017-02-13  91  };
6cca22ede8a448 drivers/gpu/drm/i915/selftests/mock_dmabuf.c Chris Wilson 2017-02-13  92  

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0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org