Re: [PATCH v11] asus-wmi: Add support for custom fan curves

From: Luke Jones
Date: Tue Sep 28 2021 - 07:56:40 EST

A change via /sys/firmware/acpi/platform_profile does disable the fan-curve until a user re-enables it.
It doesn't wipe the actual curve setting though, I thought that would be bad UX, but yes the curve is definitely disabled on profile change and will remain disabled until turned on again. At which point another profile change will disable it again.

And as stated in previous reply use of /sys/devices/platform/asus-nb-wmi/hwmon/hwmon<N>/pwm<N>_enable to check the status is stabilised (1 = manual fan).

Looking at it with fresh eyes I just spotted some things I can clean up further. Very sorry, there'll be a v15 :(

Many thanks,

On Tue, Sep 28 2021 at 13:44:32 +0200, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:

On 9/28/21 1:36 PM, Bastien Nocera wrote:
On Wed, 2021-09-08 at 11:22 +1200, Luke D. Jones wrote:
Add support for custom fan curves found on some ASUS ROG laptops.

These laptops have the ability to set a custom curve for the CPU
and GPU fans via two ACPI methods.

This patch adds two pwm<N> attributes to the hwmon sysfs,
pwm1 for CPU fan, pwm2 for GPU fan. Both are under the hwmon of the
name `asus_custom_fan_curve`. There is no safety check of the set
fan curves - this must be done in userspace.

The fans have settings [1,2,3] under pwm<N>_enable:
1. Enable and write settings out
2. Disable and use factory fan mode
3. Same as 2, additionally restoring default factory curve.

Use of 2 means that the curve the user has set is still stored and
won't be erased, but the laptop will be using its default auto-fan
mode. Re-enabling the manual mode then activates the curves again.

- pwm<N>_enable = 0 is an invalid setting.
- pwm is actually a percentage and is scaled on writing to device.

I was trying to update:
but I don't understand what files I need to check for what values to
detect whether custom fan curves were used.

Can you help me out here?

How to deal with this is actually one of my remaining questions too.

I've not looked at the new code closely yet, but if I understand
things correctly, the now code basically only allows to set 1
custom profile and setting that profile overrides the last
profile set through /sys/firmware/acpi/platform_profile.

And any write to /sys/firmware/acpi/platform_profile will
overwrite / replace the last custom set profile (if any) with
the one matching the requested platform-profile.

So basically users of custom fan profiles are expected to
disable power-profiles-daemon or at least to refrain from
making any platform_profile changes.

And if power-profile-daemon is actually active and
makes a change then any custom settings will be thrown away,
IOW p-p-d will always win. So I believe that it no longer needs
to check for custom profiles, since any time it requests a
standard profile that will overwrite any custom profile
which may be present.

Luke, do I have that right ?

Also, was this patch accepted in the pdx86 tree?

No, I still need to find/make some time to review it and
I still have the same question as you :)