From: Rodrigo Siqueira Date: Mon, 25 Aug 2025 00:46:40 +0000 (-0600) Subject: drm/amdgpu/vcn: Document IRQ per-instance irq behavior for VCN 4.0.3 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=3d9752f4f9319110896ee497e23b18897189eb14;p=users%2Fhch%2Fmisc.git drm/amdgpu/vcn: Document IRQ per-instance irq behavior for VCN 4.0.3 When examining the VCN function init, it is common to find a loop that initializes VCN rings, which uses one IRQ per instance. However, VCN 4.0.3 deviates from this pattern, as it includes a distinct field to differentiate instances, which results in a slightly different ring init. This commit makes this difference explicit by using a fixed index when initializing the ring buffer and also adds a comment. Signed-off-by: Rodrigo Siqueira Signed-off-by: Alex Deucher --- diff --git a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_3.c b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_3.c index 7b93a275ec4f..bae1ad4484ed 100644 --- a/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_3.c +++ b/drivers/gpu/drm/amd/amdgpu/vcn_v4_0_3.c @@ -212,7 +212,11 @@ static int vcn_v4_0_3_sw_init(struct amdgpu_ip_block *ip_block) ring->vm_hub = AMDGPU_MMHUB0(adev->vcn.inst[i].aid_id); sprintf(ring->name, "vcn_unified_%d", adev->vcn.inst[i].aid_id); - r = amdgpu_ring_init(adev, ring, 512, &adev->vcn.inst->irq, 0, + + /* There are no per-instance irq source IDs on 4.0.3, the IH + * packets use a separate field to differentiate instances. + */ + r = amdgpu_ring_init(adev, ring, 512, &adev->vcn.inst[0].irq, 0, AMDGPU_RING_PRIO_DEFAULT, &adev->vcn.inst[i].sched_score); if (r)