Re: [PATCH] drm/amdgpu: avoid over-handle of fence driver fini in s3 test (v2)

[Mike Lothian <mike@fireburn.co.uk>]

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Hi

Do I need to open a new bug report for this?

Cheers

Mike

On Wed, 18 Aug 2021 at 06:26, Andrey Grodzovsky <andrey.grodzovsky@amd.com>
wrote:

>
> On 2021-08-02 1:16 a.m., Guchun Chen wrote:
> > In amdgpu_fence_driver_hw_fini, no need to call drm_sched_fini to stop
> > scheduler in s3 test, otherwise, fence related failure will arrive
> > after resume. To fix this and for a better clean up, move drm_sched_fini
> > from fence_hw_fini to fence_sw_fini, as it's part of driver shutdown, and
> > should never be called in hw_fini.
> >
> > v2: rename amdgpu_fence_driver_init to amdgpu_fence_driver_sw_init,
> > to keep sw_init and sw_fini paired.
> >
> > Fixes: cd87a6dcf6af drm/amdgpu: adjust fence driver enable sequence
> > Suggested-by: Christian König <christian.koenig@amd.com>
> > Signed-off-by: Guchun Chen <guchun.chen@amd.com>
> > ---
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c |  5 ++---
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c  | 12 +++++++-----
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h   |  4 ++--
> >   3 files changed, 11 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> > index b1d2dc39e8be..9e53ff851496 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> > @@ -3646,9 +3646,9 @@ int amdgpu_device_init(struct amdgpu_device *adev,
> >
> >   fence_driver_init:
> >       /* Fence driver */
> > -     r = amdgpu_fence_driver_init(adev);
> > +     r = amdgpu_fence_driver_sw_init(adev);
> >       if (r) {
> > -             dev_err(adev->dev, "amdgpu_fence_driver_init failed\n");
> > +             dev_err(adev->dev, "amdgpu_fence_driver_sw_init failed\n");
> >               amdgpu_vf_error_put(adev, AMDGIM_ERROR_VF_FENCE_INIT_FAIL,
> 0, 0);
> >               goto failed;
> >       }
> > @@ -3988,7 +3988,6 @@ int amdgpu_device_resume(struct drm_device *dev,
> bool fbcon)
> >       }
> >       amdgpu_fence_driver_hw_init(adev);
> >
> > -
> >       r = amdgpu_device_ip_late_init(adev);
> >       if (r)
> >               return r;
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
> > index 49c5c7331c53..7495911516c2 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
> > @@ -498,7 +498,7 @@ int amdgpu_fence_driver_init_ring(struct amdgpu_ring
> *ring,
> >   }
> >
> >   /**
> > - * amdgpu_fence_driver_init - init the fence driver
> > + * amdgpu_fence_driver_sw_init - init the fence driver
> >    * for all possible rings.
> >    *
> >    * @adev: amdgpu device pointer
> > @@ -509,13 +509,13 @@ int amdgpu_fence_driver_init_ring(struct
> amdgpu_ring *ring,
> >    * amdgpu_fence_driver_start_ring().
> >    * Returns 0 for success.
> >    */
> > -int amdgpu_fence_driver_init(struct amdgpu_device *adev)
> > +int amdgpu_fence_driver_sw_init(struct amdgpu_device *adev)
> >   {
> >       return 0;
> >   }
> >
> >   /**
> > - * amdgpu_fence_driver_fini - tear down the fence driver
> > + * amdgpu_fence_driver_hw_fini - tear down the fence driver
> >    * for all possible rings.
> >    *
> >    * @adev: amdgpu device pointer
> > @@ -531,8 +531,7 @@ void amdgpu_fence_driver_hw_fini(struct
> amdgpu_device *adev)
> >
> >               if (!ring || !ring->fence_drv.initialized)
> >                       continue;
> > -             if (!ring->no_scheduler)
> > -                     drm_sched_fini(&ring->sched);
> > +
> >               /* You can't wait for HW to signal if it's gone */
> >               if (!drm_dev_is_unplugged(&adev->ddev))
> >                       r = amdgpu_fence_wait_empty(ring);
>
>
> Sorry for late notice, missed this patch. By moving drm_sched_fini
> past amdgpu_fence_wait_empty a race is created as even after you waited
> for all fences on the ring to signal the sw scheduler will keep submitting
> new jobs on the ring and so the ring won't stay empty.
>
> For hot device removal also we want to prevent any access to HW past PCI
> removal
> in order to not do any MMIO accesses inside the physical MMIO range that
> no longer
> belongs to this device after it's removal by the PCI core. Stopping all
> the schedulers prevents any MMIO
> accesses done during job submissions and that why drm_sched_fini was
> done as part of amdgpu_fence_driver_hw_fini
> and not amdgpu_fence_driver_sw_fini
>
> Andrey
>
> > @@ -560,6 +559,9 @@ void amdgpu_fence_driver_sw_fini(struct
> amdgpu_device *adev)
> >               if (!ring || !ring->fence_drv.initialized)
> >                       continue;
> >
> > +             if (!ring->no_scheduler)
> > +                     drm_sched_fini(&ring->sched);
> > +
> >               for (j = 0; j <= ring->fence_drv.num_fences_mask; ++j)
> >                       dma_fence_put(ring->fence_drv.fences[j]);
> >               kfree(ring->fence_drv.fences);
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> > index 27adffa7658d..9c11ced4312c 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.h
> > @@ -106,7 +106,6 @@ struct amdgpu_fence_driver {
> >       struct dma_fence                **fences;
> >   };
> >
> > -int amdgpu_fence_driver_init(struct amdgpu_device *adev);
> >   void amdgpu_fence_driver_force_completion(struct amdgpu_ring *ring);
> >
> >   int amdgpu_fence_driver_init_ring(struct amdgpu_ring *ring,
> > @@ -115,9 +114,10 @@ int amdgpu_fence_driver_init_ring(struct
> amdgpu_ring *ring,
> >   int amdgpu_fence_driver_start_ring(struct amdgpu_ring *ring,
> >                                  struct amdgpu_irq_src *irq_src,
> >                                  unsigned irq_type);
> > +void amdgpu_fence_driver_hw_init(struct amdgpu_device *adev);
> >   void amdgpu_fence_driver_hw_fini(struct amdgpu_device *adev);
> > +int amdgpu_fence_driver_sw_init(struct amdgpu_device *adev);
> >   void amdgpu_fence_driver_sw_fini(struct amdgpu_device *adev);
> > -void amdgpu_fence_driver_hw_init(struct amdgpu_device *adev);
> >   int amdgpu_fence_emit(struct amdgpu_ring *ring, struct dma_fence
> **fence,
> >                     unsigned flags);
> >   int amdgpu_fence_emit_polling(struct amdgpu_ring *ring, uint32_t *s,
>

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