Hi Nouveau users,
Just saw the bitching on Phoronix about lack of fan management in
nouveau (no offence Michael, it was justified ;) ).
Since it has been working flawlessly for more than a week on my desktop,
I decided to let you guys know about it and ask for testing.
Here is the code:
http://gitorious.org/linux-nouveau-pm/linux-nouveau-pm/commits/thermal
Please read the following paragraphs before pulling this branch and fry
your GPU.
The hardware and current limitations
---------------------------------------------------
This branch introduces code to drive the most common fan type (and the
most problematic one, I guess/hope). We call them PWM fan.
The other types are TOGGLE (can only be ON or OFF) and I2C (driven using
an I2C chip).
The TOGGLE fans aren't supported because I think I lack the hw (to be
confirmed).
The PWM fans are the most common ones. It supports a full range of speed
(from 0% to 100%).
The I2C-accessible fans are usually limited to high-end cards. At the
moment, the only thing we can do for them is to launch their hwmon driver.
This is due to a limitation in hwmon that doesn't let kernel drivers
accessing the i2c chips' methods. We are working with the hwmon team and
provided
a patch to support that:
http://www.spinics.net/lists/lm-sensors/msg32906.html
If you have such a fan, you can manage it from the userspace.
The implemented fan management support
-----------------------------------------------------------
Current fan management should only work on what we call PWM fans.
This work should be usable up to (not including) nva3 chipset generation.
This is because nva3+ cards all have hw to drive the speed of the fan
(pwm or i2c).
Reading the fan speed (power): cat /sys/class/drm/cardX/device/pwm0
Reading the fan speed (RPM): cat /sys/class/drm/cardX/device/fan0_input
Setting the fan management method: echo X >
/sys/class/drm/cardX/device/pwm0_enable
- X = 0: Fan management disabled, fan power set to 100%
- X = 1: Manual fan management (you can set the speed by writing
[0->100] to /sys/class/drm/cardX/device/pwm0)
- X = 2: The default automatic fan management (equivalent to X = 3 for
the moment)
- X = 3: Linear fan management. The fan speed is linearly correlated to
the temperature.
- X = 4: Target temperature management. The fan is driven to keep the
GPU to a certain temperature
The thermal zone implementation
------------------------------------------------
Since I believe thermal zones are great but massively under-used. I used
thermal zones to define some trip points.
Here are some noteworthy trip points:
- Default mode: Listen to the user commands
- Fan boost: Whenever the GPU reaches this temperature, the fan will
blow at 100%
- Downclocking: Whenever the GPU reaches this temperature, your GPU will
be downclocked to the lowest perflvl
- Critical: Whenever the GPU reaches this temperature, your computer
will shut down to prevent damages.
BIG FAT WARNING
-----------------------------
For those willing to try this, please watch your GPU temperature closely
at any time using "$ sensors" and your fingers.
If you think sensors doesn't report the right temperature, please send
us a mail with your vbios and show up on IRC (ask mupuf).
Check this before having fun with fan management, it is very important!
Installation
------------------
cd my_package_directory
git clone git://gitorious.org/linux-nouveau-pm/linux-nouveau-pm.git
git branch --track thermal origin/thermal
Then it is just a matter of compiling and testing your kernel. Please
follow your distribution's guide.
Report
------------
Please report your story on our IRC channel. Please also send your
kernel logs along with your vbios to martin.peres <at> free(dot)fr.
Conclusion
------------
Hope you like it. Keep us informed of how well it works ;)
Martin (AKA mupuf)
PS: Another testing call about power management should also follow but
there is something I want to implement before people try it.
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