Hardware 3D acceleration doesn't work anymore with the latest git kernel

[Ilia Mirkin]

On Fri, Nov 24, 2017 at 2:08 PM, Christian Zigotzky
<chzigotzky at xenosoft.de> wrote:
> On 24.11.2017 17:09, Michel Dänzer wrote:
>>
>> On 2017-11-24 03:29 PM, Christian Zigotzky wrote:
>>>
>>> Hi All,
>>>
>>> I bisected today and the first bad commit is:
>>> a4dec819c8bba6365eb893a4ca88db4dd1210110 (drm/ttm: Add helper functions
>>> to populate/map in one call (v2)) [1]
>>
>> It can't really be that commit, since it just adds functions but doesn't
>> hook them up anywhere. Presumably it's commit
>> f7871fd19389c5f64f625a4389675d0740f0dfe4 ("drm/radeon: use new TTM
>> populate/dma map helper functions") instead, which makes the radeon
>> driver rely on ttm_populate_and_map_pages, which is just a stub
>> returning -ENOMEM when neither CONFIG_SWIOTLB nor CONFIG_INTEL_IOMMU is
>> enabled.
>>
>> I can see two possible solutions:
>>
>> 1. Make ttm_populate_and_map_pages and ttm_unmap_and_unpopulate_pages
>>     work without SWIOTLB / INTEL_IOMMU as well.
>>
>> 2. Make the drivers work without ttm_populate_and_map_pages and
>>     ttm_unmap_and_unpopulate_pages again in that case.
>>
>>
>> Solution 1 would be preferable.
>>
>>
> Hello Michel,
>
> I tested the latest git version today. Unfortunately the problem with the
> hardware 3D acceleration still exist. How can I make
> ttm_populate_and_map_pages and ttm_unmap_and_unpopulate_pages work without
> SWIOTLB / INTEL_IOMMU?

Do you have SWIOTLB disabled in your .config? Try enabling it to see
if that's the issue.

Looking at your bisect log, you might have incorrectly marked some
revisions. E.g. you had a compile failure, which while isn't "good",
it's also not "bad" -- good and bad are only in reference to the
specific issue you're seeing. In such cases you can run "git bisect
skip" which will mark the commit as "unknown" and pick a different one
to try.

  -ilia