diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 968e0e6b3fa4..ec98089d98c9 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -6283,6 +6283,7 @@ enum thermal_access_mode {
 enum { /* TPACPI_THERMAL_TPEC_* */
 	TP_EC_THERMAL_TMP0 = 0x78,	/* ACPI EC regs TMP 0..7 */
 	TP_EC_THERMAL_TMP8 = 0xC0,	/* ACPI EC regs TMP 8..15 */
+	TP_EC_FUNCREV      = 0xEF,      /* ACPI EC Functional revision */
 	TP_EC_THERMAL_TMP_NA = -128,	/* ACPI EC sensor not available */
 
 	TPACPI_THERMAL_SENSOR_NA = -128000, /* Sensor not available */
@@ -6481,7 +6482,7 @@ static const struct attribute_group thermal_temp_input8_group = {
 
 static int __init thermal_init(struct ibm_init_struct *iibm)
 {
-	u8 t, ta1, ta2;
+	u8 t, ta1, ta2, ver = 0;
 	int i;
 	int acpi_tmp7;
 	int res;
@@ -6496,7 +6497,14 @@ static int __init thermal_init(struct ibm_init_struct *iibm)
 		 * 0x78-0x7F, 0xC0-0xC7.  Registers return 0x00 for
 		 * non-implemented, thermal sensors return 0x80 when
 		 * not available
+		 * The above rule is unfortunately flawed. This has been seen with
+		 * 0xC2 (power supply ID) causing thermal control problems.
+		 * The EC version can be determined by offset 0xEF and at least for
+		 * version 3 the Lenovo firmware team confirmed that registers 0xC0-0xC7
+		 * are not thermal registers.
 		 */
+		if (!acpi_ec_read(TP_EC_FUNCREV, &ver))
+			pr_warn("Thinkpad ACPI EC unable to access EC version\n");
 
 		ta1 = ta2 = 0;
 		for (i = 0; i < 8; i++) {
@@ -6506,11 +6514,13 @@ static int __init thermal_init(struct ibm_init_struct *iibm)
 				ta1 = 0;
 				break;
 			}
-			if (acpi_ec_read(TP_EC_THERMAL_TMP8 + i, &t)) {
-				ta2 |= t;
-			} else {
-				ta1 = 0;
-				break;
+			if (ver < 3) {
+				if (acpi_ec_read(TP_EC_THERMAL_TMP8 + i, &t)) {
+					ta2 |= t;
+				} else {
+					ta1 = 0;
+					break;
+				}
 			}
 		}
 		if (ta1 == 0) {
@@ -6523,9 +6533,12 @@ static int __init thermal_init(struct ibm_init_struct *iibm)
 				thermal_read_mode = TPACPI_THERMAL_NONE;
 			}
 		} else {
-			thermal_read_mode =
-			    (ta2 != 0) ?
-			    TPACPI_THERMAL_TPEC_16 : TPACPI_THERMAL_TPEC_8;
+			if (ver >= 3)
+				thermal_read_mode = TPACPI_THERMAL_TPEC_8;
+			else
+				thermal_read_mode =
+					(ta2 != 0) ?
+					TPACPI_THERMAL_TPEC_16 : TPACPI_THERMAL_TPEC_8;
 		}
 	} else if (acpi_tmp7) {
 		if (tpacpi_is_ibm() &&