fan_curve(9)

💖 fan_curve 💖 — Kernel API Manual, bestie edition

okay so this is fan_curve(9) from the Kernel API Manual: the amdgpu driver provides a sysfs API for checking and adjusting the fan control curve line. 🌀✨

Reading back the file shows you the current settings (temperature in Celsius degree and fan speed in pwm) applied to every anchor point of the curve line, and their permitted ranges if changable. 👀

Writing a desired string (with the format like "anchor_point_index temperature fan_speed_in_pwm") to the file changes the settings for the specific anchor point accordingly. 🫶

When you have finished the editing, write "c" (commit) to the file to commit your changes. ✅

If you want to reset to the default value, write "r" (reset) to the file to reset them. 🔄

There are two fan control modes supported: auto and manual. 🎀

• With auto mode, PMFW handles the fan speed control(how fan speed reacts to ASIC temperature).
• While with manual mode, users can set their own fan curve line as what described here.

Normally the ASIC is booted up with auto mode. Any settings via this interface will switch the fan control to manual mode implicitly. 👑

🌈 SEE ALSO 🌈

• Kernel file ./drivers/gpu/drm/amd/pm/amdgpu_pm.c
• amdgpu_pm_dev_state_check(9), amdgpu_pm_get_access(9), amdgpu_pm_get_access_if_active(9), amdgpu_pm_put_access(9), power_dpm_state(9), power_dpm_force_performance_level(9), pp_table(9), pp_od_clk_voltage(9), pp_features(9)
• pp_dpm_sclk pp_dpm_mclk pp_dpm_socclk pp_dpm_fclk pp_dpm_dcefclk pp_dpm_pcie(9)
• pp_power_profile_mode(9), gpu_busy_percent(9), mem_busy_percent(9), vcn_busy_percent(9), pcie_bw(9), unique_id(9), thermal_throttling_logging(9), apu_thermal_cap(9), gpu_metrics(9), smartshift_apu_power(9), smartshift_dgpu_power(9), smartshift_bias(9), board(9), baseboard_temp(9), gpuboard_temp(9), cur_node_power_limit(9), node_power(9), npm_status(9), global_ppt_resid(9), max_node_power_limit(9), baseboard_power(9), baseboard_power_limit(9), pm_policy(9), hwmon(9), acoustic_limit_rpm_threshold(9), acoustic_target_rpm_threshold(9), fan_target_temperature(9), fan_minimum_pwm(9), fan_zero_rpm_enable(9), fan_zero_rpm_stop_temperature(9)

mwah 💋 xoxo, your fan_curve(9) bestie — sourced from ./drivers/gpu/drm/amd/pm, dated October 2026. 🎀🦋