drm/amdgpu: Fix null point error

need to check adev->powerplay.pp_funcs first, becasue from
AI, the smu ip can be disabled by user, and the pp_handle
is null in this case.
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -135,7 +135,8 @@ static int acp_poweroff(struct generic_pm_domain *genpd)
 	 * 2. power off the acp tiles
 	 * 3. check and enter ulv state
 	 */
-		if (adev->powerplay.pp_funcs->set_powergating_by_smu)
+		if (adev->powerplay.pp_funcs &&
+			adev->powerplay.pp_funcs->set_powergating_by_smu)
 			amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_ACP, true);
 	}
 	return 0;
@@ -517,7 +518,8 @@ static int acp_set_powergating_state(void *handle,
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 	bool enable = state == AMD_PG_STATE_GATE ? true : false;
 
-	if (adev->powerplay.pp_funcs->set_powergating_by_smu)
+	if (adev->powerplay.pp_funcs &&
+		adev->powerplay.pp_funcs->set_powergating_by_smu)
 		amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_ACP, enable);
 
 	return 0;

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

@@ -392,7 +392,7 @@ void amdgpu_gfx_off_ctrl(struct amdgpu_device *adev, bool enable)
 	if (!(adev->powerplay.pp_feature & PP_GFXOFF_MASK))
 		return;
 
-	if (!adev->powerplay.pp_funcs->set_powergating_by_smu)
+	if (!adev->powerplay.pp_funcs || !adev->powerplay.pp_funcs->set_powergating_by_smu)
 		return;
 
 

drivers/gpu/drm/amd/amdgpu/mmhub_v1_0.c

@@ -280,7 +280,7 @@ void mmhub_v1_0_update_power_gating(struct amdgpu_device *adev,
 		return;
 
 	if (enable && adev->pg_flags & AMD_PG_SUPPORT_MMHUB) {
-		if (adev->powerplay.pp_funcs->set_powergating_by_smu)
+		if (adev->powerplay.pp_funcs && adev->powerplay.pp_funcs->set_powergating_by_smu)
 			amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_GMC, true);
 
 	}

drivers/gpu/drm/amd/amdgpu/sdma_v4_0.c

@@ -1366,7 +1366,8 @@ static int sdma_v4_0_hw_init(void *handle)
 	int r;
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
 
-	if (adev->asic_type == CHIP_RAVEN && adev->powerplay.pp_funcs->set_powergating_by_smu)
+	if (adev->asic_type == CHIP_RAVEN && adev->powerplay.pp_funcs &&
+			adev->powerplay.pp_funcs->set_powergating_by_smu)
 		amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_SDMA, false);
 
 	sdma_v4_0_init_golden_registers(adev);
@@ -1386,7 +1387,8 @@ static int sdma_v4_0_hw_fini(void *handle)
 	sdma_v4_0_ctx_switch_enable(adev, false);
 	sdma_v4_0_enable(adev, false);
 
-	if (adev->asic_type == CHIP_RAVEN && adev->powerplay.pp_funcs->set_powergating_by_smu)
+	if (adev->asic_type == CHIP_RAVEN && adev->powerplay.pp_funcs
+			&& adev->powerplay.pp_funcs->set_powergating_by_smu)
 		amdgpu_dpm_set_powergating_by_smu(adev, AMD_IP_BLOCK_TYPE_SDMA, true);
 
 	return 0;