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-rw-r--r--drivers/platform/x86/thinkpad_acpi.c31
1 files changed, 22 insertions, 9 deletions
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() &&