[PATCH 1/1] drm/amd: Add per-ring reset for vcn v4.0.5 use

[Mario Limonciello]

There is a problem occurring on VCN 4.0.5 where in some situations a job
is timing out.  This triggers a job timeout which then causes a GPU
reset for recovery.  That has exposed a number of issues with GPU reset
that have since been fixed. But also a GPU reset isn't actually needed
for this circumstance. Just restarting the ring is enough.

Add a reset callback for the ring which will stop and start VCN if the
issue happens.

Link: https://gitlab.freedesktop.org/mesa/mesa/-/issues/12528
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/3909
Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c
index 558469744f3a..3e6e8127143b 100644
--- a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c
+++ b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_5.c
@@ -1440,6 +1440,24 @@ static void vcn_v4_0_5_unified_ring_set_wptr(struct amdgpu_ring *ring)
 	}
 }
 
+static int vcn_v4_0_5_ring_reset(struct amdgpu_ring *ring, unsigned int vmid)
+{
+	struct amdgpu_device *adev = ring->adev;
+	int i;
+
+	for (i = 0; i < adev->vcn.num_vcn_inst; ++i) {
+		struct amdgpu_vcn_inst *vinst = &adev->vcn.inst[i];
+
+		if (ring != &vinst->ring_enc[0])
+			continue;
+		vcn_v4_0_5_stop(vinst);
+		vcn_v4_0_5_start(vinst);
+		break;
+	}
+
+	return amdgpu_ring_test_helper(ring);
+}
+
 static struct amdgpu_ring_funcs vcn_v4_0_5_unified_ring_vm_funcs = {
 	.type = AMDGPU_RING_TYPE_VCN_ENC,
 	.align_mask = 0x3f,
@@ -1467,6 +1485,7 @@ static struct amdgpu_ring_funcs vcn_v4_0_5_unified_ring_vm_funcs = {
 	.emit_wreg = vcn_v2_0_enc_ring_emit_wreg,
 	.emit_reg_wait = vcn_v2_0_enc_ring_emit_reg_wait,
 	.emit_reg_write_reg_wait = amdgpu_ring_emit_reg_write_reg_wait_helper,
+	.reset = vcn_v4_0_5_ring_reset,
 };
 
 /**
-- 
2.49.0