Re: [PATCH] platform/surface: Add platform profile driver

[Maximilian Luz]

On 2/11/21 4:56 PM, Hans de Goede wrote:
> Hi,
>
> On 2/8/21 10:38 PM, Maximilian Luz wrote:
> > On 2/8/21 9:27 PM, Hans de Goede wrote:
>
> <snip>
>
> > > > +static int convert_ssam_to_profile(struct ssam_device *sdev, enum ssam_tmp_profile p)
> > > > +{
> > > > +    switch (p) {
> > > > +    case SSAM_TMP_PROFILE_NORMAL:
> > > > +        return PLATFORM_PROFILE_QUIET;
> > > > +
> > > > +    case SSAM_TMP_PROFILE_BATTERY_SAVER:
> > > > +        return PLATFORM_PROFILE_LOW_POWER;
> > > > +
> > > > +    case SSAM_TMP_PROFILE_BETTER_PERFORMANCE:
> > > > +        return PLATFORM_PROFILE_BALANCED;
> > > > +
> > > > +    case SSAM_TMP_PROFILE_BEST_PERFORMANCE:
> > > > +        return PLATFORM_PROFILE_PERFORMANCE;
> > > > +
> > > > +    default:
> > > > +        dev_err(&sdev->dev, "invalid performance profile: %d", p);
> > > > +        return -EINVAL;
> > > > +    }
> > > > +}
> > >
> > > I'm not sure about the mapping which you have chosen here. I know that at least for
> > > gnome there are plans to make this stuff available in the UI:
> > >
> > > https://gitlab.gnome.org/Teams/Design/settings-mockups/-/blob/master/power/power.png
> > > http://www.hadess.net/2020/09/power-profiles-daemon-new-project.html
> >
> > Thanks for those links!
> >   
> > > Notice there are only 3 levels in the UI, which will primarily be mapped to:
> > >
> > > PLATFORM_PROFILE_LOW_POWER
> > > PLATFORM_PROFILE_BALANCED
> > > PLATFORM_PROFILE_PERFORMANCE
> > >
> > > (with fallbacks to say QUIET for LOW_POWER of there is no LOW_POWER, but that
> > > mostly is something for userspace to worry about).
> >
> > Interesting, I wasn't aware of that. I was aware of Bastien's work
> > towards implementing user-space support for this but I hadn't yet looked
> > at it in detail (e.g. the "fallback to quiet" is new to me).
>
> Note that the fallback stuff would not apply here, since you do provide
> all 3 of low-power, balanced and performance. But the current way gnome
> will handle this means that it will be impossible to select "normal" from
> the GNOME ui which feels wrong.
>
> > > And the power-profile-daemon will likely restore the last used setting on boot,
> > > meaning with your mapping that it will always switch the profile away from
> > > SSAM_TMP_PROFILE_NORMAL, which I assume is the default profile picked at boot ?
> >
> > Pretty much, yeah. AFAICT booting doesn't reset it, but hard-resetting
> > the EC does. Same difference though.
> >   
> > > So ideally we would map PLATFORM_PROFILE_BALANCED (which will be the default
> > > GNOME / power-profile-daemon setting) to SSAM_TMP_PROFILE_NORMAL.
> > >
> > > I know the ABI docs say that drivers should try to use existing values, but
> > > this seems like a good case to add a new value or 2 to the PLATFORM_PROFILE enum.
> > >
> > > During the discussion the following 2 options were given because some devices
> > > may have more then one balanced profile:
> > >
> > > PLATFORM_PROFILE_BALANCED_LOW_POWER:
> > >
> > >                   balanced-low-power:     Balances between low power consumption
> > >                                           and performance with a slight bias
> > >                                           towards low power
> > >
> > > PLATFORM_PROFILE_BALANCED_PERFORMANCE:
> > >
> > >                   balanced-performance:   Balances between performance and low
> > >                                           power consumption with a slight bias
> > >                                           towards performance
> > >
> > > I think it would be better to add 1 or both of these, if we add both
> > > we could e.g. do the following mappings:
> > >
> > > SSAM_TMP_PROFILE_BATTERY_SAVER      ->  PLATFORM_PROFILE_LOW_POWER
> > > SSAM_TMP_PROFILE_NORMAL             ->  PLATFORM_PROFILE_BALANCED_LOW_POWER
> > > SSAM_TMP_PROFILE_BETTER_PERFORMANCE ->  PLATFORM_PROFILE_BALANCED_PERFORMANCE
> > > SSAM_TMP_PROFILE_BEST_PERFORMANCE   ->  PLATFORM_PROFILE_PERFORMANCE
> > >
> > > or we could do:
> > >
> > > SSAM_TMP_PROFILE_BATTERY_SAVER      ->  PLATFORM_PROFILE_LOW_POWER
> > > SSAM_TMP_PROFILE_NORMAL             ->  PLATFORM_PROFILE_BALANCED
> > > SSAM_TMP_PROFILE_BETTER_PERFORMANCE ->  PLATFORM_PROFILE_BALANCED_PERFORMANCE
> > > SSAM_TMP_PROFILE_BEST_PERFORMANCE   ->  PLATFORM_PROFILE_PERFORMANCE
> > >
> > > I'm not sure which is best, I hope you have a better idea of that then me.
> > >
> > > I might even be wrong here and NORMAL might really be more about being QUIET
> > > then it really being BALANCED ? In which case the mapping is fine as is.
> >
> > I can only really speak on the behavior of my Surface Book 2. On that
> > device, the CPU is passively cooled, but the discrete GPU is actively
> > cooled, so I can actually only really talk about active cooling behavior
> > for the dGPU.
> >
> > On that, at least, the normal (Windows calls this 'recommended') profile
> > feels like it targets quiet operation. Using the dGPU with that profile
> > pretty much ensures that the dGPU will be limited in performance by a
> > thermal limiter (around 75°C to 80°C; at least it feels that way), while
> > the fan is somewhat audible but definitely not at maximum speed.
> > Changing the profile to any higher profile (Windows calls those 'better
> > performance' and 'best performance'), the fan becomes significantly more
> > audible. I'm not entirely sure if the performance increase can solely be
> > attributed to cooling though.
> >
> > As far as I've heard, that behavior seems to be similar on other devices
> > with fans for CPU cooling, but I can try to get some more feedback on
> > that.
> >
> > Based on all of this, I thought that this would most resemble a 'quiet'
> > profile. But I'd also be fine with your second suggestion. Calling the
> > last two options 'balanced performance' and 'performance' might be a bit
> > closer to the Windows naming scheme. It doesn't seem like the normal
> > profile does much power limiting in terms of actually capping the power
> > limit of the dGPU, so I think calling this 'balanced' would also make
> > sense to me, especially in light of Gnome's defaults.
>
> Ack.
>
> So that means that this is going to need to have a preparation patch
> adding the 2 balanced variants which I mention above. Can you take care
> of that in the next version?

Sure. Already prepared a patch for the 'balanced-performance' one over at [1].
Just needs some squashing and I can send in an updated series. Do you also want
me to add the 'balanced-low-power' version? I'd have chosen 'balanced' and
'balanced-performance' in the new mapping, so there wouldn't be any driver
right now using that.
 
> And since that prep. patch needs to go through Rafael's PM tree anyways,
> maybe also throw in a patch to make ACPI_PLATFORM_PROFILE not user selectable
> and use select on it in the thinkpad_acpi and ideapad_laptop drivers?

There's also already one at [1] for that just waiting to be sent :)

[1]: https://github.com/linux-surface/kernel/commits/s/surface-platform-profile/next

Regards,
Max

> Regards,
>
> Hans
>
>
>
>
> > > > +
> > > > +static int convert_profile_to_ssam(struct ssam_device *sdev, enum platform_profile_option p)
> > > > +{
> > > > +    switch (p) {
> > > > +    case PLATFORM_PROFILE_LOW_POWER:
> > > > +        return SSAM_TMP_PROFILE_BATTERY_SAVER;
> > > > +
> > > > +    case PLATFORM_PROFILE_QUIET:
> > > > +        return SSAM_TMP_PROFILE_NORMAL;
> > > > +
> > > > +    case PLATFORM_PROFILE_BALANCED:
> > > > +        return SSAM_TMP_PROFILE_BETTER_PERFORMANCE;
> > > > +
> > > > +    case PLATFORM_PROFILE_PERFORMANCE:
> > > > +        return SSAM_TMP_PROFILE_BEST_PERFORMANCE;
> > > > +
> > > > +    default:
> > > > +        /* This should have already been caught by platform_profile_store(). */
> > > > +        WARN(true, "unsupported platform profile");
> > > > +        return -EOPNOTSUPP;
> > > > +    }
> > > > +}
> > > > +
> > > > +static int ssam_platform_profile_get(struct platform_profile_handler *pprof,
> > > > +                     enum platform_profile_option *profile)
> > > > +{
> > > > +    struct ssam_tmp_profile_device *tpd;
> > > > +    enum ssam_tmp_profile tp;
> > > > +    int status;
> > > > +
> > > > +    tpd = container_of(pprof, struct ssam_tmp_profile_device, handler);
> > > > +
> > > > +    status = ssam_tmp_profile_get(tpd->sdev, &tp);
> > > > +    if (status)
> > > > +        return status;
> > > > +
> > > > +    status = convert_ssam_to_profile(tpd->sdev, tp);
> > > > +    if (status < 0)
> > > > +        return status;
> > > > +
> > > > +    *profile = status;
> > > > +    return 0;
> > > > +}
> > > > +
> > > > +static int ssam_platform_profile_set(struct platform_profile_handler *pprof,
> > > > +                     enum platform_profile_option profile)
> > > > +{
> > > > +    struct ssam_tmp_profile_device *tpd;
> > > > +    int tp;
> > > > +
> > > > +    tpd = container_of(pprof, struct ssam_tmp_profile_device, handler);
> > > > +
> > > > +    tp = convert_profile_to_ssam(tpd->sdev, profile);
> > > > +    if (tp < 0)
> > > > +        return tp;
> > > > +
> > > > +    return ssam_tmp_profile_set(tpd->sdev, tp);
> > > > +}
> > > > +
> > > > +static int surface_platform_profile_probe(struct ssam_device *sdev)
> > > > +{
> > > > +    struct ssam_tmp_profile_device *tpd;
> > > > +
> > > > +    tpd = devm_kzalloc(&sdev->dev, sizeof(*tpd), GFP_KERNEL);
> > > > +    if (!tpd)
> > > > +        return -ENOMEM;
> > > > +
> > > > +    tpd->sdev = sdev;
> > > > +
> > > > +    tpd->handler.profile_get = ssam_platform_profile_get;
> > > > +    tpd->handler.profile_set = ssam_platform_profile_set;
> > > > +
> > > > +    set_bit(PLATFORM_PROFILE_LOW_POWER, tpd->handler.choices);
> > > > +    set_bit(PLATFORM_PROFILE_QUIET, tpd->handler.choices);
> > > > +    set_bit(PLATFORM_PROFILE_BALANCED, tpd->handler.choices);
> > > > +    set_bit(PLATFORM_PROFILE_PERFORMANCE, tpd->handler.choices);
> > > > +
> > > > +    platform_profile_register(&tpd->handler);
> > > > +    return 0;
> > > > +}
> > > > +
> > > > +static void surface_platform_profile_remove(struct ssam_device *sdev)
> > > > +{
> > > > +    platform_profile_remove();
> > > > +}
> > > > +
> > > > +static const struct ssam_device_id ssam_platform_profile_match[] = {
> > > > +    { SSAM_SDEV(TMP, 0x01, 0x00, 0x01) },
> > > > +    { },
> > > > +};
> > > > +MODULE_DEVICE_TABLE(ssam, ssam_platform_profile_match);
> > > > +
> > > > +static struct ssam_device_driver surface_platform_profile = {
> > > > +    .probe = surface_platform_profile_probe,
> > > > +    .remove = surface_platform_profile_remove,
> > > > +    .match_table = ssam_platform_profile_match,
> > > > +    .driver = {
> > > > +        .name = "surface_platform_profile",
> > > > +        .probe_type = PROBE_PREFER_ASYNCHRONOUS,
> > > > +    },
> > > > +};
> > > > +module_ssam_device_driver(surface_platform_profile);
> > > > +
> > > > +MODULE_AUTHOR("Maximilian Luz <luzmaximilian@xxxxxxxxx>");
> > > > +MODULE_DESCRIPTION("Platform Profile Support for Surface System Aggregator Module");
> > > > +MODULE_LICENSE("GPL");