[PATCH 1/2] hwmon: (peci/cputemp) Fix crit_hyst returning delta instead of absolute temperature

From: Pradhan, Sanman

Date: Sun Mar 22 2026 - 20:25:00 EST


From: Sanman Pradhan <psanman@xxxxxxxxxxx>

The hwmon sysfs ABI expects tempN_crit_hyst to report the temperature at
which the critical condition clears, not the hysteresis delta from the
critical limit.

The peci cputemp driver currently returns tjmax - tcontrol for
crit_hyst_type, which is the hysteresis margin rather than the
corresponding absolute temperature.

Return tcontrol directly, and update the documentation accordingly.

Fixes: bf3608f338e9 ("hwmon: peci: Add cputemp driver")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sanman Pradhan <psanman@xxxxxxxxxxx>
---
Documentation/hwmon/peci-cputemp.rst | 10 ++++++----
drivers/hwmon/peci/cputemp.c | 2 +-
2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/Documentation/hwmon/peci-cputemp.rst b/Documentation/hwmon/peci-cputemp.rst
index fe0422248dc5e..266b62a46f49c 100644
--- a/Documentation/hwmon/peci-cputemp.rst
+++ b/Documentation/hwmon/peci-cputemp.rst
@@ -51,8 +51,9 @@ temp1_max Provides thermal control temperature of the CPU package
temp1_crit Provides shutdown temperature of the CPU package which
is also known as the maximum processor junction
temperature, Tjmax or Tprochot.
-temp1_crit_hyst Provides the hysteresis value from Tcontrol to Tjmax of
- the CPU package.
+temp1_crit_hyst Provides the hysteresis temperature of the CPU
+ package. Returns Tcontrol, the temperature at which
+ the critical condition clears.

temp2_label "DTS"
temp2_input Provides current temperature of the CPU package scaled
@@ -62,8 +63,9 @@ temp2_max Provides thermal control temperature of the CPU package
temp2_crit Provides shutdown temperature of the CPU package which
is also known as the maximum processor junction
temperature, Tjmax or Tprochot.
-temp2_crit_hyst Provides the hysteresis value from Tcontrol to Tjmax of
- the CPU package.
+temp2_crit_hyst Provides the hysteresis temperature of the CPU
+ package. Returns Tcontrol, the temperature at which
+ the critical condition clears.

temp3_label "Tcontrol"
temp3_input Provides current Tcontrol temperature of the CPU
diff --git a/drivers/hwmon/peci/cputemp.c b/drivers/hwmon/peci/cputemp.c
index b2fc936851e14..badec53ff4461 100644
--- a/drivers/hwmon/peci/cputemp.c
+++ b/drivers/hwmon/peci/cputemp.c
@@ -131,7 +131,7 @@ static int get_temp_target(struct peci_cputemp *priv, enum peci_temp_target_type
*val = priv->temp.target.tjmax;
break;
case crit_hyst_type:
- *val = priv->temp.target.tjmax - priv->temp.target.tcontrol;
+ *val = priv->temp.target.tcontrol;
break;
default:
ret = -EOPNOTSUPP;
--
2.34.1