drm/radeon: use packet2 for nop on hawaii with old firmware

Older firmware didn't support the new nop packet.

v2 (Andreas Boll):
 - Drop usage of packet3 for new firmware
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com> (v1)
Signed-off-by: Andreas Boll <andreas.boll.dev@gmail.com>
Cc: stable@vger.kernel.org

drivers/gpu/drm/radeon/cik.c

@@ -8259,6 +8259,7 @@ int cik_irq_process(struct radeon_device *rdev)
 static int cik_startup(struct radeon_device *rdev)
 {
 	struct radeon_ring *ring;
+	u32 nop;
 	int r;
 
 	/* enable pcie gen2/3 link */
@@ -8392,9 +8393,15 @@ static int cik_startup(struct radeon_device *rdev)
 	}
 	cik_irq_set(rdev);
 
+	if (rdev->family == CHIP_HAWAII) {
+		nop = RADEON_CP_PACKET2;
+	} else {
+		nop = PACKET3(PACKET3_NOP, 0x3FFF);
+	}
+
 	ring = &rdev->ring[RADEON_RING_TYPE_GFX_INDEX];
 	r = radeon_ring_init(rdev, ring, ring->ring_size, RADEON_WB_CP_RPTR_OFFSET,
-			     PACKET3(PACKET3_NOP, 0x3FFF));
+			     nop);
 	if (r)
 		return r;
 
@@ -8402,7 +8409,7 @@ static int cik_startup(struct radeon_device *rdev)
 	/* type-2 packets are deprecated on MEC, use type-3 instead */
 	ring = &rdev->ring[CAYMAN_RING_TYPE_CP1_INDEX];
 	r = radeon_ring_init(rdev, ring, ring->ring_size, RADEON_WB_CP1_RPTR_OFFSET,
-			     PACKET3(PACKET3_NOP, 0x3FFF));
+			     nop);
 	if (r)
 		return r;
 	ring->me = 1; /* first MEC */
@@ -8413,7 +8420,7 @@ static int cik_startup(struct radeon_device *rdev)
 	/* type-2 packets are deprecated on MEC, use type-3 instead */
 	ring = &rdev->ring[CAYMAN_RING_TYPE_CP2_INDEX];
 	r = radeon_ring_init(rdev, ring, ring->ring_size, RADEON_WB_CP2_RPTR_OFFSET,
-			     PACKET3(PACKET3_NOP, 0x3FFF));
+			     nop);
 	if (r)
 		return r;
 	/* dGPU only have 1 MEC */