[PATCH 01/10] drm/amdgpu/gfx6: Fixup emit_cntxcntl()

Timur Kristóf <[email protected]> Mon, 3 Aug 2026 15:23:00 +0200
Newsgroups org.freedesktop.lists.amd-gfx
Message-ID <[email protected]>
Set bits on dword 2 like GFX7-8 except load_global_uconfig
which doesn't exist on GFX6.

Emit VS_PARTIAL_FLUSH before VGT_FLUSH like GFX7-8.

For reference see old PAL which explains the bit fields in
this register and that load_global_uconfig doesn't exist on GFX6
and also see gfx_v7_ring_emit_cntxcntl() for the GFX7 code
which this commit follows.

Fixes: 2cd46ad22383 ("drm/amdgpu: add graphic pipeline implementation for si v8")
Signed-off-by: Timur Kristóf <[email protected]>
---
 drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c | 28 ++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c b/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c
index cd2a14ecdba8..0cbaae73a0bf 100644
--- a/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gfx_v6_0.c
@@ -1882,11 +1882,13 @@ static int gfx_v6_0_ring_test_ring(struct amdgpu_ring *ring)
 	return r;
 }
 
-static void gfx_v6_0_ring_emit_vgt_flush(struct amdgpu_ring *ring)
+static void gfx_v6_0_ring_emit_event_write(struct amdgpu_ring *ring,
+					   uint32_t event_type,
+					   uint32_t event_index)
 {
 	amdgpu_ring_write(ring, PACKET3(PACKET3_EVENT_WRITE, 0));
-	amdgpu_ring_write(ring, EVENT_TYPE(VGT_FLUSH) |
-		EVENT_INDEX(0));
+	amdgpu_ring_write(ring, EVENT_TYPE(event_type) |
+				EVENT_INDEX(event_index));
 }
 
 static void gfx_v6_0_ring_emit_fence(struct amdgpu_ring *ring, u64 addr,
@@ -2997,10 +2999,22 @@ static uint64_t gfx_v6_0_get_gpu_clock_counter(struct amdgpu_device *adev)
 
 static void gfx_v6_ring_emit_cntxcntl(struct amdgpu_ring *ring, uint32_t flags)
 {
-	if (flags & AMDGPU_HAVE_CTX_SWITCH)
-		gfx_v6_0_ring_emit_vgt_flush(ring);
+	u32 dw2 = 0x80000000; /* set load_enable otherwise this package is just NOPs */
+
+	if (flags & AMDGPU_HAVE_CTX_SWITCH) {
+		gfx_v6_0_ring_emit_event_write(ring, VS_PARTIAL_FLUSH, 4);
+		gfx_v6_0_ring_emit_event_write(ring, VGT_FLUSH, 0);
+
+		/* set load_global_config (load_global_uconfig doesn't exist on GFX6) */
+		dw2 |= 0x1;
+		/* set load_cs_sh_regs */
+		dw2 |= 0x01000000;
+		/* set load_per_context_state & load_gfx_sh_regs */
+		dw2 |= 0x10002;
+	}
+
 	amdgpu_ring_write(ring, PACKET3(PACKET3_CONTEXT_CONTROL, 1));
-	amdgpu_ring_write(ring, 0x80000000);
+	amdgpu_ring_write(ring, dw2);
 	amdgpu_ring_write(ring, 0);
 }
 
@@ -3527,7 +3541,7 @@ static const struct amdgpu_ring_funcs gfx_v6_0_ring_funcs_gfx = {
 		14 + 14 + 14 + /* gfx_v6_0_ring_emit_fence x3 for user fence, vm fence */
 		7 + 4 + /* gfx_v6_0_ring_emit_pipeline_sync */
 		SI_FLUSH_GPU_TLB_NUM_WREG * 5 + 7 + 6 + /* gfx_v6_0_ring_emit_vm_flush */
-		3 + 2 + /* gfx_v6_ring_emit_cntxcntl including vgt flush */
+		3 + 2 + 2 + /* gfx_v6_ring_emit_cntxcntl including VGT flush */
 		5, /* SURFACE_SYNC */
 	.emit_ib_size = 6, /* gfx_v6_0_ring_emit_ib */
 	.emit_ib = gfx_v6_0_ring_emit_ib,
-- 
2.55.0