hwmon/f71805f: Document the fan control features
Document the different fan control methods, list their options, and give some hints for best results. Signed-off-by: Jean Delvare <khali@linux-fr.org>
This commit is contained in:
parent
315c7113b5
commit
e9cea64601
1 changed files with 38 additions and 4 deletions
|
@ -13,8 +13,8 @@ Thanks to Denis Kieft from Barracuda Networks for the donation of a
|
||||||
test system (custom Jetway K8M8MS motherboard, with CPU and RAM) and
|
test system (custom Jetway K8M8MS motherboard, with CPU and RAM) and
|
||||||
for providing initial documentation.
|
for providing initial documentation.
|
||||||
|
|
||||||
Thanks to Kris Chen from Fintek for answering technical questions and
|
Thanks to Kris Chen and Aaron Huang from Fintek for answering technical
|
||||||
providing additional documentation.
|
questions and providing additional documentation.
|
||||||
|
|
||||||
Thanks to Chris Lin from Jetway for providing wiring schematics and
|
Thanks to Chris Lin from Jetway for providing wiring schematics and
|
||||||
answering technical questions.
|
answering technical questions.
|
||||||
|
@ -28,8 +28,7 @@ capabilities. It can monitor up to 9 voltages (counting its own power
|
||||||
source), 3 fans and 3 temperature sensors.
|
source), 3 fans and 3 temperature sensors.
|
||||||
|
|
||||||
This chip also has fan controlling features, using either DC or PWM, in
|
This chip also has fan controlling features, using either DC or PWM, in
|
||||||
three different modes (one manual, two automatic). The driver doesn't
|
three different modes (one manual, two automatic).
|
||||||
support these features yet.
|
|
||||||
|
|
||||||
The driver assumes that no more than one chip is present, which seems
|
The driver assumes that no more than one chip is present, which seems
|
||||||
reasonable.
|
reasonable.
|
||||||
|
@ -103,3 +102,38 @@ sensor. Each channel can be used for connecting either a thermal diode
|
||||||
or a thermistor. The driver reports the currently selected mode, but
|
or a thermistor. The driver reports the currently selected mode, but
|
||||||
doesn't allow changing it. In theory, the BIOS should have configured
|
doesn't allow changing it. In theory, the BIOS should have configured
|
||||||
everything properly.
|
everything properly.
|
||||||
|
|
||||||
|
|
||||||
|
Fan Control
|
||||||
|
-----------
|
||||||
|
|
||||||
|
Both PWM (pulse-width modulation) and DC fan speed control methods are
|
||||||
|
supported. The right one to use depends on external circuitry on the
|
||||||
|
motherboard, so the driver assumes that the BIOS set the method
|
||||||
|
properly. The driver will report the method, but won't let you change
|
||||||
|
it.
|
||||||
|
|
||||||
|
When the PWM method is used, you can select the operating frequency,
|
||||||
|
from 187.5 kHz (default) to 31 Hz. The best frequency depends on the
|
||||||
|
fan model. As a rule of thumb, lower frequencies seem to give better
|
||||||
|
control, but may generate annoying high-pitch noise. Fintek recommends
|
||||||
|
not going below 1 kHz, as the fan tachometers get confused by lower
|
||||||
|
frequencies as well.
|
||||||
|
|
||||||
|
When the DC method is used, Fintek recommends not going below 5 V, which
|
||||||
|
corresponds to a pwm value of 106 for the driver. The driver doesn't
|
||||||
|
enforce this limit though.
|
||||||
|
|
||||||
|
Three different fan control modes are supported:
|
||||||
|
|
||||||
|
* Manual mode
|
||||||
|
You ask for a specific PWM duty cycle or DC voltage.
|
||||||
|
|
||||||
|
* Fan speed mode
|
||||||
|
You ask for a specific fan speed. This mode assumes that pwm1
|
||||||
|
corresponds to fan1, pwm2 to fan2 and pwm3 to fan3.
|
||||||
|
|
||||||
|
* Temperature mode
|
||||||
|
You define 3 temperature/fan speed trip points, and the fan speed is
|
||||||
|
adjusted depending on the measured temperature, using interpolation.
|
||||||
|
This mode is not yet supported by the driver.
|
||||||
|
|
Loading…
Reference in a new issue