Linux 4.11: Reported regressions as of Tuesday, 20176-03-14

[Michel Dänzer]

On 15/03/17 04:33 PM, Christian König wrote:
> Am 15.03.2017 um 02:59 schrieb Michel Dänzer:
>> [ Moving this sub-thread to the amd-gfx mailing list ]
>>
>> On 14/03/17 07:02 PM, Thorsten Leemhuis wrote:
>>> Hi! Find below my first regression report for Linux 4.11. It lists 9
>>> regressions I'm currently aware of.
>> [...]
>>
>>> Desc: DRM BUG while initializing cape verde (2nd card)
>>> Repo: 2017-03-13 https://bugzilla.kernel.org/show_bug.cgi?id=194867
>>> Stat: n/a
>>> Note: patch proposed by reporter
>> I don't see any patch.
>>
>> Looks like the amdgpu driver has never fully initialized GDS support for
>> SI family GPUs, and this now triggers the DRM_MM_BUG_ON which was added
>> to drm_mm_init in 4.11.
>>
>> AMD folks, should this be addressed by fleshing out SI GDS support, or
>> by completely disabling GDS initialization for SI?
> Uff, good question. IIRC GDS was significantly different between SI and
> CIK in the hardware and requires pinned buffers on SI (userspace needs
> to know the physical address of the buffer).
> 
> So the current implementation most likely doesn't work as expected.
> 
> I would say disable it for now, but keep any existing code for at least
> one release. If nobody finds time to fix it properly (which is likely)
> we can throw away that and move on.

Any takers for 4.11? :)


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer