[PATCH] drm/ttm: Make sure BOs being swapped out are cacheable

[Alex Deucher]

On Fri, Jan 27, 2017 at 3:22 AM, Christian König
<christian.koenig at amd.com> wrote:
> Am 27.01.2017 um 08:30 schrieb Daniel Vetter:
>>
>> On Fri, Jan 27, 2017 at 07:23:58AM +0100, Thomas Hellstrom wrote:
>>>
>>> On 01/27/2017 03:29 AM, Michel Dänzer wrote:
>>>>
>>>> On 26/01/17 09:46 AM, Sinclair Yeh wrote:
>>>>>
>>>>> On Wed, Jan 25, 2017 at 10:49:33AM +0100, Christian König wrote:
>>>>>>
>>>>>> Am 25.01.2017 um 10:25 schrieb Thomas Hellstrom:
>>>>>>>
>>>>>>> On 01/25/2017 09:21 AM, Michel Dänzer wrote:
>>>>>>>>
>>>>>>>> From: Michel Dänzer <michel.daenzer at amd.com>
>>>>>>>>
>>>>>>>> The current caching state may not be tt_cached, even though the
>>>>>>>> placement contains TTM_PL_FLAG_CACHED, because placement can contain
>>>>>>>> multiple caching flags. Trying to swap out such a BO would trip up
>>>>>>>> the
>>>>>>>>
>>>>>>>>         BUG_ON(ttm->caching_state != tt_cached);
>>>>>>>>
>>>>>>>> in ttm_tt_swapout.
>>>>>>>>
>>>>>>>> Cc: stable at vger.kernel.org
>>>>>>>> Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
>>>>>>>
>>>>>>> Reviewed-by: Thomas Hellstrom <thellstrom at vmware.com>
>>>>>>
>>>>>> Reviewed-by: Christian König <christian.koenig at amd.com>.
>>>>>
>>>>> Reviewed-by: Sinclair Yeh <syeh at vmware.com>
>>>>
>>>> Thanks for the reviews! Via which tree should we merge this?
>>>>
>>>>
>>> I don't maintain a TTM tree any longer. Let's check with Daniel if he
>>> can merge it through drm-misc.
>>
>> I'm trying very hard not to get volunteered for ttm maintainer :-)
>
>
> Yeah, ok I volunteer. Wanted to take that over for a while anyway.
>
>> Nominally Alex&Christian have drm-misc commit rights, but they haven't
>> used them yet. But I think merging through drm-misc would make sense,
>> there's regular pull request trains for both -next and -fixes.
>
>
> Completely agree on merging it through drm-misc. Going to give my push
> rights a try today.
>
>> Or merge through the amd tree with Dave's ack, but I'd really like to get
>> amd folks
>> into the drm-misc group ...
>
>
> I've got a few more already reviewed TTM changes which are currently waiting
> to be pushed upstream where amdgpu has dependencies on.
>
> Going to sync with Alex so he sends his pull requests with those changes to
> Dave after the merge of the depending changes.
>
> If you want to object that just merging through the AMD tree would be
> simpler, I agree but I actually want to do this exercise at least once :)

I was thinking of including this in my -fixes pull next week, but I
don't have a strong preference either way.  The other ttm changes are
pretty intertwined with amdgpu changes so I think it would be easier
to take them in via the amdgpu tree.  In the future we can adjust
that.

Alex