#define mmMP1_SMN_C2PMSG_90                                                                            0x029a
 #define mmMP1_SMN_C2PMSG_90_BASE_IDX                                                                   0
 
+#define mmMP1_SMN_C2PMSG_66_V13_0_4                    0x0282
+#define mmMP1_SMN_C2PMSG_66_V13_0_4_BASE_IDX            1
+
+#define mmMP1_SMN_C2PMSG_82_V13_0_4                    0x0292
+#define mmMP1_SMN_C2PMSG_82_V13_0_4_BASE_IDX            1
+
+#define mmMP1_SMN_C2PMSG_90_V13_0_4                    0x029a
+#define mmMP1_SMN_C2PMSG_90_V13_0_4_BASE_IDX           1
+
 /* SMU 13.0.5 has its specific mailbox messaging registers */
 
 #define mmMP1_C2PMSG_2                                                                            (0xbee142 + 0xb00000 / 4)
 
        if (adev->ip_versions[MP1_HWIP][0] == IP_VERSION(13, 0, 5))
                *arg = RREG32_SOC15(MP1, 0, mmMP1_C2PMSG_34);
+       else if (adev->ip_versions[MP1_HWIP][0] == IP_VERSION(13, 0, 4))
+               *arg = RREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_82_V13_0_4);
        else
                *arg = RREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_82);
 }
        for ( ; timeout > 0; timeout--) {
                if (adev->ip_versions[MP1_HWIP][0] == IP_VERSION(13, 0, 5))
                        reg = RREG32_SOC15(MP1, 0, mmMP1_C2PMSG_33);
+               else if (adev->ip_versions[MP1_HWIP][0] == IP_VERSION(13, 0, 4))
+                       reg = RREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_90_V13_0_4);
                else
                        reg = RREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_90);
                if ((reg & MP1_C2PMSG_90__CONTENT_MASK) != 0)
                if (adev->ip_versions[MP1_HWIP][0] == IP_VERSION(13, 0, 5)) {
                        msg_idx = RREG32_SOC15(MP1, 0, mmMP1_C2PMSG_2);
                        prm     = RREG32_SOC15(MP1, 0, mmMP1_C2PMSG_34);
+               } else if (adev->ip_versions[MP1_HWIP][0] == IP_VERSION(13, 0, 4)) {
+                       msg_idx = RREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_66_V13_0_4);
+                       prm     = RREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_82_V13_0_4);
                } else {
                        msg_idx = RREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_66);
                        prm     = RREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_82);
                WREG32_SOC15(MP1, 0, mmMP1_C2PMSG_33, 0);
                WREG32_SOC15(MP1, 0, mmMP1_C2PMSG_34, param);
                WREG32_SOC15(MP1, 0, mmMP1_C2PMSG_2, msg);
+       } else if (adev->ip_versions[MP1_HWIP][0] == IP_VERSION(13, 0, 4)) {
+               WREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_90_V13_0_4, 0);
+               WREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_82_V13_0_4, param);
+               WREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_66_V13_0_4, msg);
        } else {
                WREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_90, 0);
                WREG32_SOC15(MP1, 0, mmMP1_SMN_C2PMSG_82, param);