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 <[e-mail]>
Reviewed-by: Christian König <[e-mail]> (v1)
Signed-off-by: Andreas Boll <[e-mail]>
Cc: [e-mail]

drivers/gpu/drm/radeon/cik.c

···
 static int cik_startup(struct radeon_device *rdev)
 {
 	struct radeon_ring *ring;
+	u32 nop;
 	int r;
 
 	/* enable pcie gen2/3 link */
···
 	}
 	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;
 
···
 	/* 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 */
···
 	/* 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 */