Hi Karthik,
Expose pwm[1-3]_enable for fan control mode selection.
Value of 0 runs fan at full speed.
A value of 1 keeps user fan-table control active, while value 2
switches back to firmware control.
Update Xe hwmon ABI documentation for pwm[1-3]_enable.
v2:
- Use xe helpers for dmesg logs.
- Update kernel version in Xe hwmon documentation.
- Correct level of some dmesg logs.
Signed-off-by: Karthik Poosa <karthik.poosa@intel.com>
Assisted-by: Codex:gpt-5-4
---
.../ABI/testing/sysfs-driver-intel-xe-hwmon | 11 +++
drivers/gpu/drm/xe/xe_hwmon.c | 91 ++++++++++++++++++-
2 files changed, 100 insertions(+), 2 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon b/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
index 7383898890aa..effc7d38ce1f 100644
--- a/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
+++ b/Documentation/ABI/testing/sysfs-driver-intel-xe-hwmon
@@ -330,3 +330,14 @@ Description: RW. Target fan PWM duty value in the range 0..255. 0 is zero
fan speed and 255 is 100% fan speed.
Only supported for particular Intel Xe graphics platforms.
+
+What: /sys/bus/pci/drivers/xe/.../hwmon/hwmon<i>/pwm[1-3]_enable
+Date: July 2026
+KernelVersion: 7.2
+Contact: intel-xe@lists.freedesktop.org
+Description: RW. Fan control mode selector.
+
+ Use value 0 to run fans at full speed. Use value 1 to enable
+ user table control and value 2 to use firmware default behavior.
+
+ Only supported for particular Intel Xe graphics platforms.
diff --git a/drivers/gpu/drm/xe/xe_hwmon.c b/drivers/gpu/drm/xe/xe_hwmon.c
index d3379727b1a9..fa9dbadd5fd6 100644
--- a/drivers/gpu/drm/xe/xe_hwmon.c
+++ b/drivers/gpu/drm/xe/xe_hwmon.c
@@ -123,6 +123,15 @@ struct xe_hwmon_energy_info {
long accum_energy;
};
+enum xe_fan_pwm_enable_mode {
+ /** @XE_FAN_PWM_FULL_SPEED: force all user table points to full speed */
+ XE_FAN_PWM_FULL_SPEED = 0,
+ /** @XE_FAN_PWM_MANUAL_USER_TABLE: use the driver-managed user table */
+ XE_FAN_PWM_MANUAL_USER_TABLE = 1,
+ /** @XE_FAN_PWM_AUTO_STOCK_TABLE: use the firmware stock table */
+ XE_FAN_PWM_AUTO_STOCK_TABLE = 2,
+};
+
enum fan_table_type {
/** @STOCK_FAN_TABLE: firmware-provided fan table */
STOCK_FAN_TABLE,
@@ -169,6 +178,10 @@ struct xe_hwmon_fan_info {
u32 max_rps;
/** @min_pwm: minimum fan PWM */
u32 min_pwm;
+ /** @pwm_enable_mode: current xe_fan_pwm_enable_mode */
+ u8 pwm_enable_mode;
+ /** @is_full_speed: flag indicating if fan is in full speed */
+ bool is_full_speed;
};
/**
@@ -803,7 +816,9 @@ static const struct hwmon_channel_info * const hwmon_info[] = {
HWMON_CHANNEL_INFO(energy, HWMON_E_INPUT | HWMON_E_LABEL, HWMON_E_INPUT | HWMON_E_LABEL),
HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_MAX, HWMON_F_INPUT | HWMON_F_MAX,
HWMON_F_INPUT | HWMON_F_MAX),
- HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT, HWMON_PWM_INPUT, HWMON_PWM_INPUT),
+ HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
+ HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
NULL
};
@@ -1033,7 +1048,8 @@ static int xe_hwmon_activate_user_fan_table(struct xe_hwmon *hwmon, u8 fan,
}
fi->fan_table[USER_FAN_TABLE].fan_control_point_count = point_count;
-
+ fi->pwm_enable_mode = XE_FAN_PWM_MANUAL_USER_TABLE;
+ fi->is_full_speed = is_full_speed;
return 0;
}
@@ -1046,6 +1062,11 @@ static int xe_hwmon_set_user_fan_pwm(struct xe_hwmon *hwmon, u8 fan, u8 pwm)
int ret;
int point;
+ if (fi->pwm_enable_mode == XE_FAN_PWM_AUTO_STOCK_TABLE) {
+ xe_dbg(hwmon->xe, "fan %d manual table is not active, cannot set pwm\n", fan);
+ return -EINVAL;
+ }
+
/* Read user table fan point count, if it is not set, activate the user table */
ret = xe_hwmon_get_fan_point_count(hwmon, fan, &point_count, USER_FAN_TABLE);
if (ret)
@@ -1078,6 +1099,9 @@ static int xe_hwmon_set_user_fan_pwm(struct xe_hwmon *hwmon, u8 fan, u8 pwm)
xe_dbg(hwmon->xe, "failed to update fan %d user table count, ret=%d\n", fan, ret);
return ret;
}
+
+ fi->pwm_enable_mode = XE_FAN_PWM_MANUAL_USER_TABLE;
+ fi->is_full_speed = false;
return 0;
}
@@ -1134,6 +1158,9 @@ static int xe_hwmon_read_fan_control_info(struct xe_hwmon *hwmon)
fi->fan_table[STOCK_FAN_TABLE].fcp[point].speed);
}
+ /* Set PWM enable mode to automatic i.e stock table in use. */
+ fi->pwm_enable_mode = XE_FAN_PWM_AUTO_STOCK_TABLE;
+
/* Read minimum fan PWM */
ret = xe_hwmon_pcode_read_fan_control(hwmon, FSC_READ_FAN_MIN_PWM, fan,
&fi->min_pwm);
@@ -1585,6 +1612,7 @@ xe_hwmon_pwm_is_visible(struct xe_hwmon *hwmon, u32 attr, int channel)
switch (attr) {
case hwmon_pwm_input:
+ case hwmon_pwm_enable:
return 0644;
default:
return 0;
@@ -1669,6 +1697,9 @@ xe_hwmon_pwm_read(struct xe_hwmon *hwmon, u32 attr, int channel, long *val)
*val = DIV_ROUND_CLOSEST(fi->fan_table[USER_FAN_TABLE].fcp[0].speed *
U8_MAX, 100);
return 0;
+ case hwmon_pwm_enable:
+ *val = fi->is_full_speed ? XE_FAN_PWM_FULL_SPEED : fi->pwm_enable_mode;
+ return 0;
default:
return -EOPNOTSUPP;
}
@@ -1677,11 +1708,15 @@ xe_hwmon_pwm_read(struct xe_hwmon *hwmon, u32 attr, int channel, long *val)
static int
xe_hwmon_pwm_write(struct xe_hwmon *hwmon, u32 attr, int channel, long val)
{
+ struct xe_tile *root_tile = xe_device_get_root_tile(hwmon->xe);
+ struct xe_hwmon_fan_info *fi;
int ret = 0;
if (channel < 0 || channel >= FAN_MAX)
return -EINVAL;
+ fi = &hwmon->fi[channel];
+
mutex_lock(&hwmon->hwmon_lock);
switch (attr) {
@@ -1692,10 +1727,62 @@ xe_hwmon_pwm_write(struct xe_hwmon *hwmon, u32 attr, int channel, long val)
}
ret = xe_hwmon_set_user_fan_pwm(hwmon, channel, (u8)val);
break;
+ case hwmon_pwm_enable:
+ if (val == XE_FAN_PWM_FULL_SPEED) {
+ /* Set fans at full speed. */
+ ret = xe_hwmon_activate_user_fan_table(hwmon, channel, true,
+ STOCK_FAN_TABLE);
+ if (ret) {
+ xe_warn(hwmon->xe,
+ "full speed enable for fan %d failed, ret=%d\n",
+ channel, ret);
+ }
+ } else if (val == XE_FAN_PWM_MANUAL_USER_TABLE) {
+ /*
+ * Manual fan speed control using user fan table.
+ * If user fan table is not programmed, it would be initialized with
nit: s/programmed/populated/
+ * clamped stock points which allows manual control with some + * default points. + */ + ret = xe_hwmon_activate_user_fan_table(hwmon, channel, false, + USER_FAN_TABLE);
How can USER_FAN_TABLE be the source of itself ? Should it be STOCK_FAN_TABLE ?
Thanks, Soham
+ if (ret) {
+ xe_warn(hwmon->xe,
+ "failed to activate user fan table for fan %d, ret=%d\n",
+ channel, ret);
+ }
+ } else if (val == XE_FAN_PWM_AUTO_STOCK_TABLE) {
+ /* Switch to stock table specifying the user points to 0. */
+ ret = xe_pcode_write_timeout(root_tile,
+ PCODE_MBOX(FAN_SPEED_CONTROL,
+ FSC_WRITE_NUM_FAN_CONTROL_POINTS,
+ channel),
+ 0, XE_PCODE_FAN_CONTROL_TIMEOUT_MS);
+ if (ret) {
+ xe_warn(hwmon->xe,
+ "failed to disable user fan table for fan %d, ret=%d\n",
+ channel, ret);
+ break;
+ }
+ xe_dbg(hwmon->xe,
+ "automatic control enabled for fan %d using stock table\n",
+ channel);
+ ret = 0;
+ } else {
+ ret = -EINVAL;
+ }
+ break;
default:
ret = -EOPNOTSUPP;
break;
}
+
+ /* Update PWM enable mode and full speed status if no error occurred */
+ if (!ret && attr == hwmon_pwm_enable) {
+ fi->pwm_enable_mode = val;
+ fi->is_full_speed = (val == XE_FAN_PWM_FULL_SPEED);
+ }
+
mutex_unlock(&hwmon->hwmon_lock);
return ret;