Yes, I see the checking in backend_bind:        if (!amdgpu_gtt_mgr_is_allocated(bo_mem))                return 0; OK, then my only concern is your â??insteadâ?? assumes amdgpu_gtt_mgr_is_allocated means gart is bound, how about: bool amdgpu_gtt_is_bound(struct ttm_tt *ttm) {    return amdgpu_gtt_mgr_is_allocated(bo_mem); } Why I prefer to keep is_bound for naming is we only can get gpu offset after gtt is bound not check if node is allocated. Regards, David Zhou On 2017å¹´10æ??23æ?¥ 16:11, Christian König wrote: > Am 23.10.2017 um 09:33 schrieb Chunming Zhou: >> using ttm->state == tt_bound seems make more sense. > > That won't work. We set ttm->state = tt_bound even when we haven't > allocated GART space. > > That's also a reason why I wanted to remove it, the name is confusing. > > Christian. > >> >> >> On 2017å¹´10æ??20æ?¥ 17:20, Christian König wrote: >>> From: Christian König <christian.koenig at amd.com> >>> >>> use amdgpu_gtt_mgr_is_allocated() instead. >>> >>> Signed-off-by: Christian König <christian.koenig at amd.com> >>> --- >>>  drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 2 +- >>>  drivers/gpu/drm/amd/amdgpu/amdgpu_object.h | 2 +- >>>  drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c   | 15 +++++---------- >>>  drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h   | 1 - >>>  4 files changed, 7 insertions(+), 13 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c >>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c >>> index 8b4ed8a98a18..71a0c1a477ae 100644 >>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c >>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c >>> @@ -980,7 +980,7 @@ u64 amdgpu_bo_gpu_offset(struct amdgpu_bo *bo) >>>  { >>>      WARN_ON_ONCE(bo->tbo.mem.mem_type == TTM_PL_SYSTEM); >>>      WARN_ON_ONCE(bo->tbo.mem.mem_type == TTM_PL_TT && >>> -            !amdgpu_ttm_is_bound(bo->tbo.ttm)); >>> + !amdgpu_gtt_mgr_is_allocated(&bo->tbo.mem)); >>> WARN_ON_ONCE(!ww_mutex_is_locked(&bo->tbo.resv->lock) && >>>               !bo->pin_count); >>>      WARN_ON_ONCE(bo->tbo.mem.start == AMDGPU_BO_INVALID_OFFSET); >>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h >>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h >>> index 428aae048f4b..3affcc497be6 100644 >>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h >>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h >>> @@ -187,7 +187,7 @@ static inline u64 amdgpu_bo_mmap_offset(struct >>> amdgpu_bo *bo) >>>  static inline bool amdgpu_bo_gpu_accessible(struct amdgpu_bo *bo) >>>  { >>>      switch (bo->tbo.mem.mem_type) { >>> -   case TTM_PL_TT: return amdgpu_ttm_is_bound(bo->tbo.ttm); >>> +   case TTM_PL_TT: return amdgpu_gtt_mgr_is_allocated(&bo->tbo.mem); >>>      case TTM_PL_VRAM: return true; >>>      default: return false; >>>      } >>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c >>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c >>> index 32c822f3db11..1c9faa1a53ce 100644 >>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c >>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c >>> @@ -861,8 +861,10 @@ static int amdgpu_ttm_backend_bind(struct >>> ttm_tt *ttm, >>>          bo_mem->mem_type == AMDGPU_PL_OA) >>>          return -EINVAL; >>>  -   if (!amdgpu_gtt_mgr_is_allocated(bo_mem)) >>> +   if (!amdgpu_gtt_mgr_is_allocated(bo_mem)) { >>> +       gtt->offset = AMDGPU_BO_INVALID_OFFSET; >>>          return 0; >>> +   } >>>       spin_lock(>t->adev->gtt_list_lock); >>>      flags = amdgpu_ttm_tt_pte_flags(gtt->adev, ttm, bo_mem); >>> @@ -882,13 +884,6 @@ static int amdgpu_ttm_backend_bind(struct >>> ttm_tt *ttm, >>>      return r; >>>  } >>>  -bool amdgpu_ttm_is_bound(struct ttm_tt *ttm) >>> -{ >>> -   struct amdgpu_ttm_tt *gtt = (void *)ttm; >>> - >>> -   return gtt && !list_empty(>t->list); >>> -} >>> - >>>  int amdgpu_ttm_bind(struct ttm_buffer_object *bo, struct >>> ttm_mem_reg *bo_mem) >>>  { >>>      struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev); >>> @@ -899,7 +894,7 @@ int amdgpu_ttm_bind(struct ttm_buffer_object >>> *bo, struct ttm_mem_reg *bo_mem) >>>      struct ttm_place placements; >>>      int r; >>>  -   if (!ttm || amdgpu_ttm_is_bound(ttm)) >>> +   if (!ttm || amdgpu_gtt_mgr_is_allocated(bo_mem)) >>>          return 0; >>>       tmp = bo->mem; >>> @@ -960,7 +955,7 @@ static int amdgpu_ttm_backend_unbind(struct >>> ttm_tt *ttm) >>>      if (gtt->userptr) >>>          amdgpu_ttm_tt_unpin_userptr(ttm); >>>  -   if (!amdgpu_ttm_is_bound(ttm)) >>> +   if (gtt->offset == AMDGPU_BO_INVALID_OFFSET) >>>          return 0; >>>       /* unbind shouldn't be done for GDS/GWS/OA in >>> ttm_bo_clean_mm */ >>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h >>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h >>> index abd4084982a3..89a71abc71e0 100644 >>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h >>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h >>> @@ -90,7 +90,6 @@ int amdgpu_fill_buffer(struct amdgpu_bo *bo, >>>              struct dma_fence **fence); >>>   int amdgpu_mmap(struct file *filp, struct vm_area_struct *vma); >>> -bool amdgpu_ttm_is_bound(struct ttm_tt *ttm); >>>  int amdgpu_ttm_bind(struct ttm_buffer_object *bo, struct >>> ttm_mem_reg *bo_mem); >>>  int amdgpu_ttm_recover_gart(struct amdgpu_device *adev); >> >