[drm-intel:for-linux-next 18/27] drivers/gpu//drm/i915/i915_gem_gtt.c:1087: error: 'iter' is used uninitialized in this function

[kbuild test robot]

tree:   git://anongit.freedesktop.org/drm-intel for-linux-next
head:   a883241c3922000b21b58b5740c55badfe09940f
commit: 0a03852e049af91da9ae70326c44bb5d9b0d377a [18/27] drm/i915: support 2M pages for the 48b PPGTT
config: x86_64-randconfig-b0-10091604 (attached as .config)
compiler: gcc-4.4 (Debian 4.4.7-8) 4.4.7
reproduce:
        git checkout 0a03852e049af91da9ae70326c44bb5d9b0d377a
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All errors (new ones prefixed by >>):

   cc1: warnings being treated as errors
   drivers/gpu//drm/i915/i915_gem_gtt.c: In function 'intel_ppat_get':
   drivers/gpu//drm/i915/i915_gem_gtt.c:2969: error: 'entry' may be used uninitialized in this function
   drivers/gpu//drm/i915/i915_gem_gtt.c: In function 'gen8_ppgtt_insert_3lvl':
   drivers/gpu//drm/i915/i915_gem_gtt.c:1007: error: 'iter.sg' is used uninitialized in this function
   drivers/gpu//drm/i915/i915_gem_gtt.c:1008: error: 'iter.dma' may be used uninitialized in this function
   drivers/gpu//drm/i915/i915_gem_gtt.c: In function 'gen8_ppgtt_insert_4lvl':
>> drivers/gpu//drm/i915/i915_gem_gtt.c:1087: error: 'iter' is used uninitialized in this function

vim +/iter +1087 drivers/gpu//drm/i915/i915_gem_gtt.c

0a03852e0 Matthew Auld   2017-10-06  1078  
894ccebee Chris Wilson   2017-02-15  1079  static void gen8_ppgtt_insert_4lvl(struct i915_address_space *vm,
4a234c5fa Matthew Auld   2017-06-22  1080  				   struct i915_vma *vma,
894ccebee Chris Wilson   2017-02-15  1081  				   enum i915_cache_level cache_level,
894ccebee Chris Wilson   2017-02-15  1082  				   u32 unused)
894ccebee Chris Wilson   2017-02-15  1083  {
894ccebee Chris Wilson   2017-02-15  1084  	struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm);
894ccebee Chris Wilson   2017-02-15  1085  	struct sgt_dma iter = {
4a234c5fa Matthew Auld   2017-06-22  1086  		.sg = vma->pages->sgl,
894ccebee Chris Wilson   2017-02-15 @1087  		.dma = sg_dma_address(iter.sg),
894ccebee Chris Wilson   2017-02-15  1088  		.max = iter.dma + iter.sg->length,
894ccebee Chris Wilson   2017-02-15  1089  	};
894ccebee Chris Wilson   2017-02-15  1090  	struct i915_page_directory_pointer **pdps = ppgtt->pml4.pdps;
0a03852e0 Matthew Auld   2017-10-06  1091  
0a03852e0 Matthew Auld   2017-10-06  1092  	if (vma->page_sizes.sg > I915_GTT_PAGE_SIZE) {
0a03852e0 Matthew Auld   2017-10-06  1093  		gen8_ppgtt_insert_huge_entries(vma, pdps, &iter, cache_level);
0a03852e0 Matthew Auld   2017-10-06  1094  	} else {
4a234c5fa Matthew Auld   2017-06-22  1095  		struct gen8_insert_pte idx = gen8_insert_pte(vma->node.start);
894ccebee Chris Wilson   2017-02-15  1096  
0a03852e0 Matthew Auld   2017-10-06  1097  		while (gen8_ppgtt_insert_pte_entries(ppgtt, pdps[idx.pml4e++],
0a03852e0 Matthew Auld   2017-10-06  1098  						     &iter, &idx, cache_level))
9e89f9ee3 Chris Wilson   2017-02-25  1099  			GEM_BUG_ON(idx.pml4e >= GEN8_PML4ES_PER_PML4);
f9b5b782c Michel Thierry 2015-07-30  1100  	}
0a03852e0 Matthew Auld   2017-10-06  1101  }
f9b5b782c Michel Thierry 2015-07-30  1102  

:::::: The code at line 1087 was first introduced by commit
:::::: 894ccebee2b0e606ba9638d20dd87b33568482d7 drm/i915: Micro-optimise gen8_ppgtt_insert_entries()

:::::: TO: Chris Wilson <chris at chris-wilson.co.uk>
:::::: CC: Chris Wilson <chris at chris-wilson.co.uk>

---
0-DAY kernel test infrastructure                Open Source Technology Center
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