[PATCH 01/11] drm/amdgpu: hw ring should be empty when gpu reset

[David1.Zhou@xxxxxxx (Chunming Zhou)]

Change-Id: I08ca5a805f590cc7aad0e9ccd91bd5925bb216e2
Signed-off-by: Chunming Zhou <David1.Zhou at amd.com>
Reviewed-by: Edward O'Callaghan <funfunctor at folklore1984.net>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h        |  1 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c |  1 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c   | 11 +++++++++++
 3 files changed, 13 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index c0e4164..a0dea0d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1253,6 +1253,7 @@ int amdgpu_ib_ring_tests(struct amdgpu_device *adev);
 int amdgpu_ring_alloc(struct amdgpu_ring *ring, unsigned ndw);
 void amdgpu_ring_insert_nop(struct amdgpu_ring *ring, uint32_t count);
 void amdgpu_ring_generic_pad_ib(struct amdgpu_ring *ring, struct amdgpu_ib *ib);
+void amdgpu_ring_reset(struct amdgpu_ring *ring);
 void amdgpu_ring_commit(struct amdgpu_ring *ring);
 void amdgpu_ring_undo(struct amdgpu_ring *ring);
 int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 5e984cf..b470e5a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -2117,6 +2117,7 @@ int amdgpu_gpu_reset(struct amdgpu_device *adev)
 			continue;
 		kthread_park(ring->sched.thread);
 		amd_sched_hw_job_reset(&ring->sched);
+		amdgpu_ring_reset(ring);
 	}
 	/* after all hw jobs are reset, hw fence is meaningless, so force_completion */
 	amdgpu_fence_driver_force_completion(adev);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
index 9989e25..75e1da6 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
@@ -110,6 +110,17 @@ void amdgpu_ring_generic_pad_ib(struct amdgpu_ring *ring, struct amdgpu_ib *ib)
 		ib->ptr[ib->length_dw++] = ring->nop;
 }
 
+void amdgpu_ring_reset(struct amdgpu_ring *ring)
+{
+       u32 rptr = amdgpu_ring_get_rptr(ring);
+
+       ring->wptr = rptr;
+       ring->wptr &= ring->ptr_mask;
+
+       mb();
+       amdgpu_ring_set_wptr(ring);
+}
+
 /**
  * amdgpu_ring_commit - tell the GPU to execute the new
  * commands on the ring buffer
-- 
1.9.1