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

[Luke Jones]

On Tue, Sep 28 2021 at 13:56:05 +0200, Hans de Goede 
<hdegoede@xxxxxxxxxx> wrote:
> Hi,
>
> On 9/28/21 1:43 PM, Luke Jones wrote:
> >  Sure, the path is similar to 
> > /sys/devices/platform/asus-nb-wmi/hwmon/hwmon4/pwm1_enable where 
> > hwmon4 will likely be different depending on init, and pwm2_enable 
> > is the second fan if it exists. The values are 1,2,3 - where 1 = fan 
> > curve enabled/manual, 2 = auto. 3 here is custom extra that writes 
> > default curve back then defaults to 2.
> >
> >  As I understand it, this should be adhering to the accepted kernel 
> > standard, so if you use this for ASUS laptops, then it should carry 
> > over to other brands that implement it also.
>
> Ah, so this is a bit different then how I thought this would work
> (this is probably better though).
>
> <snip>
>
> > > >   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.
>
> Quoting Documentation/hwmon/sysfs-interface.rst
>
> `pwm[1-*]_enable`
>                 Fan speed control method:
>
>                 - 0: no fan speed control (i.e. fan at full speed)
>                 - 1: manual fan speed control enabled (using 
> `pwm[1-*]`)
>                 - 2+: automatic fan speed control enabled
>
> 1 normally means the fans runs at a fixed speed, but you are using it
> for the custom/manual profile, which is still a temp<->pwm table,
> right?
>
> I guess this make sense since full manual control is not supported
> and this keeps "2" aka auto as being the normal factory auto
> setting which is good.
>
> Bastien is this interface usable for p-p-d ?
>
> I guess that it is a bit annoying that you need to figure out
> the # in the hwmon# part of the path, but there will be only
> one hwmon child.
>
> You could also go through /sys/class/hwmon but then you really
> have no idea which one to use. Ideally we would have some way
> to indicate that there is a hmwon class-dev associated with
> /sys/firmware/acpi/platform_profile but as we mentioned before
> we should defer coming up with a generic solution for this
> until we have more then 1 user, so that we hopefully get the
> generic solution right in one go.

If it's at all helpful, I named the interface as 
"asus_custom_fan_curve". I use this to verify I have the correct hwmon 
for asusctl. Open to suggestions on that.

> Regards,
>
> Hans
>
>
>
>
>
> > > >   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.
> > > >
> > > >   Notes:
> > > >   - 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:
> > >  
> > > https://gitlab.freedesktop.org/hadess/power-profiles-daemon/-/merge_requests/80
> > >  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?
> > >
> > >  Also, was this patch accepted in the pdx86 tree?
> > >
> > >  Cheers