Re: [External] Re: [PATCH] [RFC] Documentation: Add documentation for new platform_profile sysfs attribute

[Mark Pearson]

Hi Elia

On 27/10/2020 05:19, Elia Devito wrote:
> Hi to all,
>
> In data martedì 27 ottobre 2020 08:54:44 CET, Hans de Goede ha scritto:
> > Hi,
> >
> > On 10/26/20 8:55 PM, Mark Pearson wrote:
> > > Thanks Hans
> > >
> > > On 26/10/2020 14:33, Hans de Goede wrote:
> > > > Hi Mark,
> > > >
> > > > Thank you for this new version.
> > > >
> > > > On 10/26/20 6:44 PM, Mark Pearson wrote:
> > > > > From: Hans de Goede <hdegoede@xxxxxxxxxx>
> > >
> > > <snip>
> > >
> > > > > +
> > > > > +If for some reason there is no good match when mapping then a new
> > > > > profile-name +may be added. Drivers which wish to introduce new
> > > > > profile-names must: +1. Have very good reasons to do so.
> > > > > +2. Add the new profile-name to this document, so that future drivers
> > > > > which also +   have a similar problem can use the same new.
> > > >
> > > > s/same new/same name/
> > >
> > > I've read this document so many times...I'm not sure how I missed that
> > > one. Thanks.>
> > > > > + Usually new profile-names will
> > > > > +   be added to the "extra profile-names" section of this document. But
> > > > > in some +   cases the set of standard profile-names may be extended.
> > > >
> > > > With the change from a more generic API to this new one more targeted
> > > > towards DPTF I would drop this part.
> > >
> > > OK - I have some questions then related to this change, below
> > >
> > > > > +
> > > > > +What:        /sys/firmware/acpi/platform_profile_choices
> > > > > +Date:        October 2020
> > > > > +Contact:    Hans de Goede <hdegoede@xxxxxxxxxx>
> > > > > +Description:
> > > > > +        Reading this file gives a space separated list of profiles
> > > > > +        supported for this device.
> > > > > +
> > > > > +        Drivers must use the following standard profile-names whenever
> > > > > +        possible:
> > > > > +
> > > > > +        low-power:        Emphasises low power consumption
> > > > > +        quiet:            Offers quieter operation (lower fan
> > > > > +                    speed but with higher performance and
> > > > > +                    temperatures then seen in low-power
> > > >
> > > > I think the description here is a bit too specific, this may cause
> > > > userspace to have expectations which are not necessary true. I would
> > > > describe this as just:
> > > >
> > > >          quiet:            Emphasises quieter operation
> > >
> > > Agreed. I'll update
> > >
> > > > > +        balanced:        Balance between low power consumption
> > > > > +                    and performance
> > > > > +        performance:        Emphasises performance (and may lead to
> > > > > +                    higher temperatures and fan speeds)
> > > > > +
> > > > > +        Userspace may expect drivers to offer at least several of these
> > > > > +        standard profile-names! If none of the above are a good match
> > > > > +        for some of the drivers profiles, then drivers may use one of
> > > > > +        these extra profile-names:
> > > > > +        <reserved for future use>
> > > > > +
> > >
> > > If we remove the extra profile-names section above then I think it should
> > > be removed here too. If someone wants to add a new 'mode' then it would
> > > be added to the list of 'standard names', and becomes a new option.
> > > Wanted to check I'm not missing something important.
> > You are completely right, any references to an extra profile-names section
> > should be removed here too. I did intend to add that it should be removed
> > here too, but I forgot.
> >
> > > > > +What:        /sys/firmware/acpi/platform_profile
> > > > > +Date:        October 2020
> > > > > +Contact:    Hans de Goede <hdegoede@xxxxxxxxxx>
> > > > > +Description:
> > > > > +        Reading this file gives the current selected profile for this
> > > > > +        device. Writing this file with one of the strings from
> > > > > +        available_profiles changes the profile to the new value.
> > > >
> > > > The part about custom profiles below may be dropped. That was intended
> > > > for use with e.g. GPUs but since this now strictly is a system-level
> > > > profile API, the part below can be dropped now.
> > >
> > > Agreed
> > >
> > > > > +
> > > > > +        Reading this file may also return "custom". This is intended
> > > > > for
> > > > > +        drivers which have and export multiple knobs. Such drivers may
> > > > > +        very well still want to offer a set of profiles for easy of use
> > > > > +        and to be able to offer a consistent standard API (this API) to
> > > > > +        userspace for configuring their performance. The "custom" value
> > > > > +        is intended for when ai user has directly configured the knobs
> > > > > +        (through e.g. some advanced control-panel for a GPU) and the
> > > > > +        knob values do not match any of the presets represented by the
> > > > > +        platform-profiles. In this case writing this file will
> > > > > +        override the modifications and restore the selected presets.
> > > > > +
> > > >
> > > > Regards,
> > > >
> > > > Hans
> > >
> > > Thanks!
> > > mark
> >
> > Regards,
> >
> > Hans
>
> This look good,
> only thing is that hp-wmi driver need a cool profile (Emphasises the computer
> cool to touch), if you can add it would be perfect.
>
> Regards
> Elia
Is low-power is different to cool? I figured low-power was going to be 
cool so combined them.
I could call it low-power-cool if that helps? It seems a little clunky 
but not too bad. I'm sure the user space folks can put sunglasses on it 
or something ;)

Mark