[2/2] drm/ttm: make TT creation purely optional v3

[Michel Dänzer]

On 2020-08-06 9:13 a.m., Christian König wrote:
> Am 05.08.20 um 18:16 schrieb Michel Dänzer:
>> On 2020-06-29 5:19 p.m., Christian König wrote:
>>> We only need the page array when the BO is about to be accessed.
>>>
>>> So not only populate, but also create it on demand.
>>>
>>> v2: move NULL check into ttm_tt_create()
>>> v3: fix the occurrence in ttm_bo_kmap_ttm as well
>> This broke amdgpu userptr functionality for me, in particular all
>> GL_AMD_pinned_memory piglit tests, e.g.
>>
>> .../piglit/bin/amd_pinned_memory decrement-offset -auto -fbo
>> Offset is decremented, no wait.
>> Mesa: User error: GL_INVALID_OPERATION in glBufferData
>> [...]
>> Unexpected GL error: GL_INVALID_OPERATION 0x502
>> (Error at tests/spec/amd_pinned_memory/test.c:214)
>> PIGLIT: {"result": "fail" }
> 
> But no crashes? I would have expected a NULL pointer deref if we have
> missed call path.

No crashes. Since a GL error is raised, my guess would be that an ioctl
which was previously succeeding is now returning an error.


-- 
Earthling Michel Dänzer               |               https://redhat.com
Libre software enthusiast             |             Mesa and X developer