PWM fan speed too high

[Klaus-Peter Schrage]

Am 24.07.2014 16:35, schrieb poma:
>> https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/tree/drivers/gpu/drm/nouveau/core/subdev/therm/fan.c?h=linux-3.14.y#n195
>>
>> static void
>> nouveau_therm_fan_set_defaults(struct nouveau_therm *therm)
>> {
>>     struct nouveau_therm_priv *priv = (void *)therm;
>>
>>     priv->fan->bios.pwm_freq = 0;
>>     priv->fan->bios.min_duty = 0;
>>     priv->fan->bios.max_duty = 100;
>>     priv->fan->bios.bump_period = 500;
>>     priv->fan->bios.slow_down_period = 2000;
>> /*XXX: talk to mupuf */
>> #if 0
>>     priv->fan->bios.linear_min_temp = 40;
>>     priv->fan->bios.linear_max_temp = 85;
>> #endif
>> }
>>
>> https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/tree/drivers/gpu/drm/nouveau/core/subdev/therm/fan.c?h=linux-3.15.y#n195
>>
>> static void
>> nouveau_therm_fan_set_defaults(struct nouveau_therm *therm)
>> {
>>     struct nouveau_therm_priv *priv = (void *)therm;
>>
>>     priv->fan->bios.pwm_freq = 0;
>>     priv->fan->bios.min_duty = 0;
>>     priv->fan->bios.max_duty = 100;
>>     priv->fan->bios.bump_period = 500;
>>     priv->fan->bios.slow_down_period = 2000;
>>     priv->fan->bios.linear_min_temp = 40;
>>     priv->fan->bios.linear_max_temp = 85;
>> }
>>
>> "drm/nouveau/therm: let the vbios decide on the automatic fan
>> management mode"
>> https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/drivers/gpu/drm/nouveau/core/subdev/therm/fan.c?h=linux-3.15.y&id=0e994d6
>>
>>     This should fix automatic fan management on fermi cards who do not
>> have 0x46 entries in the thermal table.
>>     On my nve6, the blob sets the default linear range from 40°C to
>> 100°C but my nvcf's default values are 40°C to 85°C.
>>     Let's keep 85 as a default for everyone.
>>
>> Here refers to NVCF, your is NV108 (GK208) i.e. GeForce GT 630
>> http://nouveau.freedesktop.org/wiki/CodeNames/
>>
>> The fan is really LOUD all the time. How do I make it more quiet?
>> http://nouveau.freedesktop.org/wiki/FAQ/#index25h3
>> ... In the mean time, if you are interested, you can read
>> PowerManagement and/or contact mupuf on the #nouveau freenode IRC
>> channel.
>>
>
> Fan at full speed on Dell T1650
> https://bugzilla.redhat.com/show_bug.cgi?id=1121331
>
> [NVCF] PWM fan speed too high
> https://bugs.freedesktop.org/show_bug.cgi?id=80901
>
> [Nouveau] hwmon: question about the sysfs interface
> http://lists.freedesktop.org/archives/nouveau/2014-July/018012.html
>
>
> nouveau funky fan club

Thank you, Mr. Fantomas, for your thorough analysis, which gave some 
insight even to me! But I can refrain from trying a kernel recompile 
which I last did a decade or so ago (although, as far as I can remember, 
this is not such a kind of rocket science as one might guess from the 
recent thread on "new kernel & rebooting").

So I'll wait until a clever patch finds its way into the 
(Fedora-)kernel. Meanwhile I stick to the 3.14-kernel.