drm/amdgpu: Restore HQD persistent state register

On GFX v9.4.3, compute queue MQD is populated using the values in HQD
persistent state register. Hence don't clear the values on module
unload, instead restore it to the default reset value so that MQD is
initialized correctly during next module load. In particular, preload
flag needs to be set on compute queue MQD, otherwise it could cause
uninitialized values being used at device reset state resulting in EDC.

Signed-off-by: Lijo Lazar <[email protected]>
Reviewed-by: Hawking Zhang <[email protected]>
Reviewed-by: Asad Kamal <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

Author: Lijo Lazar

drivers/gpu/drm/amd/amdgpu/gfx_v9_4_3.c

@@ -46,6 +46,7 @@ MODULE_FIRMWARE("amdgpu/gc_9_4_3_rlc.bin");
 #define RLCG_UCODE_LOADING_START_ADDRESS 0x00002000L
 
 #define GOLDEN_GB_ADDR_CONFIG 0x2a114042
+#define CP_HQD_PERSISTENT_STATE_DEFAULT 0xbe05301
 
 struct amdgpu_gfx_ras gfx_v9_4_3_ras;
 
@@ -1736,7 +1737,7 @@ static int gfx_v9_4_3_xcc_q_fini_register(struct amdgpu_ring *ring,
 
 	WREG32_SOC15_RLC(GC, GET_INST(GC, xcc_id), regCP_HQD_IQ_TIMER, 0);
 	WREG32_SOC15_RLC(GC, GET_INST(GC, xcc_id), regCP_HQD_IB_CONTROL, 0);
-	WREG32_SOC15_RLC(GC, GET_INST(GC, xcc_id), regCP_HQD_PERSISTENT_STATE, 0);
+	WREG32_SOC15_RLC(GC, GET_INST(GC, xcc_id), regCP_HQD_PERSISTENT_STATE, CP_HQD_PERSISTENT_STATE_DEFAULT);
 	WREG32_SOC15_RLC(GC, GET_INST(GC, xcc_id), regCP_HQD_PQ_DOORBELL_CONTROL, 0x40000000);
 	WREG32_SOC15_RLC(GC, GET_INST(GC, xcc_id), regCP_HQD_PQ_DOORBELL_CONTROL, 0);
 	WREG32_SOC15_RLC(GC, GET_INST(GC, xcc_id), regCP_HQD_PQ_RPTR, 0);