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Diffstat (limited to 'kernel/Documentation/thermal/nouveau_thermal')
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diff --git a/kernel/Documentation/thermal/nouveau_thermal b/kernel/Documentation/thermal/nouveau_thermal new file mode 100644 index 000000000..60bc29357 --- /dev/null +++ b/kernel/Documentation/thermal/nouveau_thermal @@ -0,0 +1,82 @@ +Kernel driver nouveau +=================== + +Supported chips: +* NV43+ + +Authors: Martin Peres (mupuf) <martin.peres@free.fr> + +Description +--------- + +This driver allows to read the GPU core temperature, drive the GPU fan and +set temperature alarms. + +Currently, due to the absence of in-kernel API to access HWMON drivers, Nouveau +cannot access any of the i2c external monitoring chips it may find. If you +have one of those, temperature and/or fan management through Nouveau's HWMON +interface is likely not to work. This document may then not cover your situation +entirely. + +Temperature management +-------------------- + +Temperature is exposed under as a read-only HWMON attribute temp1_input. + +In order to protect the GPU from overheating, Nouveau supports 4 configurable +temperature thresholds: + + * Fan_boost: Fan speed is set to 100% when reaching this temperature; + * Downclock: The GPU will be downclocked to reduce its power dissipation; + * Critical: The GPU is put on hold to further lower power dissipation; + * Shutdown: Shut the computer down to protect your GPU. + +WARNING: Some of these thresholds may not be used by Nouveau depending +on your chipset. + +The default value for these thresholds comes from the GPU's vbios. These +thresholds can be configured thanks to the following HWMON attributes: + + * Fan_boost: temp1_auto_point1_temp and temp1_auto_point1_temp_hyst; + * Downclock: temp1_max and temp1_max_hyst; + * Critical: temp1_crit and temp1_crit_hyst; + * Shutdown: temp1_emergency and temp1_emergency_hyst. + +NOTE: Remember that the values are stored as milli degrees Celcius. Don't forget +to multiply! + +Fan management +------------ + +Not all cards have a drivable fan. If you do, then the following HWMON +attributes should be available: + + * pwm1_enable: Current fan management mode (NONE, MANUAL or AUTO); + * pwm1: Current PWM value (power percentage); + * pwm1_min: The minimum PWM speed allowed; + * pwm1_max: The maximum PWM speed allowed (bypassed when hitting Fan_boost); + +You may also have the following attribute: + + * fan1_input: Speed in RPM of your fan. + +Your fan can be driven in different modes: + + * 0: The fan is left untouched; + * 1: The fan can be driven in manual (use pwm1 to change the speed); + * 2; The fan is driven automatically depending on the temperature. + +NOTE: Be sure to use the manual mode if you want to drive the fan speed manually + +NOTE2: When operating in manual mode outside the vbios-defined +[PWM_min, PWM_max] range, the reported fan speed (RPM) may not be accurate +depending on your hardware. + +Bug reports +--------- + +Thermal management on Nouveau is new and may not work on all cards. If you have +inquiries, please ping mupuf on IRC (#nouveau, freenode). + +Bug reports should be filled on Freedesktop's bug tracker. Please follow +http://nouveau.freedesktop.org/wiki/Bugs |