Re: [PATCH 10/10] drm/ttm: flip the switch for driver allocated resources v2

["Christian König" <ckoenig.leichtzumerken@gmail.com>]

Am 07.06.21 um 12:15 schrieb Thomas Hellström (Intel):
>
> On 6/2/21 12:09 PM, Christian König wrote:
>> Instead of both driver and TTM allocating memory finalize embedding the
>> ttm_resource object as base into the driver backends.
>>
>> v2: fix typo in vmwgfx grid mgr and double init in amdgpu_vram_mgr.c
>>
>> Signed-off-by: Christian König <christian.koenig@amd.com>
>> Reviewed-by: Matthew Auld <matthew.auld@intel.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_gtt_mgr.c   | 44 ++++++--------
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.c    |  2 +-
>>   .../gpu/drm/amd/amdgpu/amdgpu_res_cursor.h    |  5 +-
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c  | 60 +++++++++----------
>>   drivers/gpu/drm/drm_gem_vram_helper.c         |  3 +-
>>   drivers/gpu/drm/nouveau/nouveau_bo.c          |  8 +--
>>   drivers/gpu/drm/nouveau/nouveau_mem.c         | 11 ++--
>>   drivers/gpu/drm/nouveau/nouveau_mem.h         | 14 ++---
>>   drivers/gpu/drm/nouveau/nouveau_ttm.c         | 32 +++++-----
>>   drivers/gpu/drm/ttm/ttm_range_manager.c       | 23 +++----
>>   drivers/gpu/drm/ttm/ttm_resource.c            | 18 +-----
>>   drivers/gpu/drm/ttm/ttm_sys_manager.c         | 12 ++--
>>   drivers/gpu/drm/vmwgfx/vmwgfx_gmrid_manager.c | 24 ++++----
>>   drivers/gpu/drm/vmwgfx/vmwgfx_thp.c           | 27 ++++-----
>>   include/drm/ttm/ttm_range_manager.h           |  3 +-
>>   include/drm/ttm/ttm_resource.h                | 43 ++++++-------
>>   16 files changed, 140 insertions(+), 189 deletions(-)
> ...
>>   diff --git a/drivers/gpu/drm/ttm/ttm_range_manager.c 
>> b/drivers/gpu/drm/ttm/ttm_range_manager.c
>> index ce5d07ca384c..c32e1aee2481 100644
>> --- a/drivers/gpu/drm/ttm/ttm_range_manager.c
>> +++ b/drivers/gpu/drm/ttm/ttm_range_manager.c
>> @@ -58,7 +58,7 @@ to_range_manager(struct ttm_resource_manager *man)
>>   static int ttm_range_man_alloc(struct ttm_resource_manager *man,
>>                      struct ttm_buffer_object *bo,
>>                      const struct ttm_place *place,
>> -                   struct ttm_resource *mem)
>> +                   struct ttm_resource **res)
>>   {
>>       struct ttm_range_manager *rman = to_range_manager(man);
>>       struct ttm_range_mgr_node *node;
>> @@ -83,37 +83,30 @@ static int ttm_range_man_alloc(struct 
>> ttm_resource_manager *man,
>>         spin_lock(&rman->lock);
>>       ret = drm_mm_insert_node_in_range(mm, &node->mm_nodes[0],
>> -                      mem->num_pages, bo->page_alignment, 0,
>> +                      node->base.num_pages,
>> +                      bo->page_alignment, 0,
>>                         place->fpfn, lpfn, mode);
>>       spin_unlock(&rman->lock);
>>   -    if (unlikely(ret)) {
>> +    if (unlikely(ret))
>>           kfree(node);
>> -    } else {
>> -        mem->mm_node = &node->mm_nodes[0];
>> -        mem->start = node->mm_nodes[0].start;
>> -    }
>> +    else
>> +        node->base.start = node->mm_nodes[0].start;
>>         return ret;
>>   }
>
> Looks like this patch forgets to assign *@res. Null pointer derefs 
> when testing i915.

I should really CC the Intel list for TTM patches as well. The CI system 
should have spotted that.

>
> BTW shouldn't we return the struct ttm_resource ptr here rather than 
> passing it as an argument?

Yeah, good idea.

Thanks for the report,
Christian.

>
> /Thomas
>
>