Re: [PATCH 03/15] dma-buf & drm/amdgpu: remove dma_resv workaround

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

Am 20.04.22 um 21:28 schrieb Zack Rusin:
> [SNIP]
>> To figure out what it is could you try the following code fragment:
>>
>> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c
>> b/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c
>> index f46891012be3..a36f89d3f36d 100644
>> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c
>> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_validation.c
>> @@ -288,7 +288,7 @@ int vmw_validation_add_bo(struct
>> vmw_validation_context *ctx,
>>                   val_buf->bo = ttm_bo_get_unless_zero(&vbo->base);
>>                   if (!val_buf->bo)
>>                           return -ESRCH;
>> -               val_buf->num_shared = 0;
>> +               val_buf->num_shared = 16;
>>                   list_add_tail(&val_buf->head, &ctx->bo_list);
>>                   bo_node->as_mob = as_mob;
>>                   bo_node->cpu_blit = cpu_blit;
> Fails the same BUG_ON with num_fences and max_fences == 0.

Thanks for testing this.

So the buffer object is not reserved through 
vmw_validation_bo_reserve(), but comes from somewhere else. 
Unfortunately I absolutely can't find where that's coming from.

Do you have some documentation howto setup vmwgfx? E.g. sample VM which 
I can download somewhere etc..

Thanks,
Christian.

>
> z