[PATCH v5 1/6] drm/amd/display: wait for fence without holding reservation lock

[Grodzovsky, Andrey]

This series is on top of drm-misc because of panfrost and lima drovers 
which are missing form amd-staging-drm-next. Once i land it in drm-misc 
I will merge and p[ush it into drm-next.

Andrey

On 4/22/19 10:35 PM, Dieter Nützel wrote:
> Hello Andrey,
>
> this series can't apply (brake on #3) on top of amd-staging-drm-next.
> v2 works (Thu, 11 Apr 2019).
>
> Dieter
>
> Am 18.04.2019 17:00, schrieb Andrey Grodzovsky:
>> From: Christian König <ckoenig.leichtzumerken at gmail.com>
>>
>> Don't block others while waiting for the fences to finish, concurrent
>> submission is perfectly valid in this case and holding the lock can
>> prevent killed applications from terminating.
>>
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>> Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
>> ---
>>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 13 ++++++++-----
>>  1 file changed, 8 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> index 380a7f9..ad4f0e5 100644
>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> @@ -4814,23 +4814,26 @@ static void amdgpu_dm_commit_planes(struct
>> drm_atomic_state *state,
>>              continue;
>>          }
>>
>> +        abo = gem_to_amdgpu_bo(fb->obj[0]);
>> +
>> +        /* Wait for all fences on this FB */
>> +        r = reservation_object_wait_timeout_rcu(abo->tbo.resv, true,
>> +                            false,
>> +                            MAX_SCHEDULE_TIMEOUT);
>> +        WARN_ON(r < 0);
>> +
>>          /*
>>           * TODO This might fail and hence better not used, wait
>>           * explicitly on fences instead
>>           * and in general should be called for
>>           * blocking commit to as per framework helpers
>>           */
>> -        abo = gem_to_amdgpu_bo(fb->obj[0]);
>>          r = amdgpu_bo_reserve(abo, true);
>>          if (unlikely(r != 0)) {
>>              DRM_ERROR("failed to reserve buffer before flip\n");
>>              WARN_ON(1);
>>          }
>>
>> -        /* Wait for all fences on this FB */
>> - WARN_ON(reservation_object_wait_timeout_rcu(abo->tbo.resv, true, 
>> false,
>> -                                        MAX_SCHEDULE_TIMEOUT) < 0);
>> -
>>          amdgpu_bo_get_tiling_flags(abo, &tiling_flags);
>>
>>          amdgpu_bo_unreserve(abo);