drm/amd/pm/smu11: BACO is supported when it's in BACO state

Return true early if ASIC is in BACO state already, no need
to talk to SMU. It can fix the issue that driver was not
calling BACO exit at all in runtime pm resume, and a timing
issue leading to a PCI AER error happened eventually.

Fixes: 8795e182 ("PCI/portdrv: Don't disable AER reporting in get_port_device_capability()")
Suggested-by: NLijo Lazar <lijo.lazar@amd.com>
Signed-off-by: NGuchun Chen <guchun.chen@amd.com>
Reviewed-by: NLijo Lazar <lijo.lazar@amd.com>
Reviewed-by: NEvan Quan <evan.quan@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/swsmu/smu11/smu_v11_0.c

@@ -1588,6 +1588,10 @@ bool smu_v11_0_baco_is_support(struct smu_context *smu)
 	if (amdgpu_sriov_vf(smu->adev) || !smu_baco->platform_support)
 		return false;
 
+	/* return true if ASIC is in BACO state already */
+	if (smu_v11_0_baco_get_state(smu) == SMU_BACO_STATE_ENTER)
+		return true;
+
 	/* Arcturus does not support this bit mask */
 	if (smu_cmn_feature_is_supported(smu, SMU_FEATURE_BACO_BIT) &&
 	   !smu_cmn_feature_is_enabled(smu, SMU_FEATURE_BACO_BIT))