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SubjectRe: [RESEND][PATCH 7/8] thermal: cooling: Check Energy Model type in cpufreq_cooling and devfreq_cooling
On 21-03-22, 09:57, Lukasz Luba wrote:
> The Energy Model can now be artificial, which means the power values
> are mathematically generated to leverage EAS while not expected to be on
> an uniform scale with other devices providing power information. If this
> EM type is in use, the thermal governor IPA should not be allowed to
> operate, since the relation between cooling devices is not properly
> defined. Thus, it might be possible that big GPU has lower power values
> than a Little CPU. To mitigate a misbehaviour of the thermal control
> algorithm, simply do not register the cooling device as IPA's power
> actor.
>
> Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
> ---
> drivers/thermal/cpufreq_cooling.c | 2 +-
> drivers/thermal/devfreq_cooling.c | 8 +++++---
> 2 files changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c
> index 0bfb8eebd126..b8151d95a806 100644
> --- a/drivers/thermal/cpufreq_cooling.c
> +++ b/drivers/thermal/cpufreq_cooling.c
> @@ -328,7 +328,7 @@ static inline bool em_is_sane(struct cpufreq_cooling_device *cpufreq_cdev,
> struct cpufreq_policy *policy;
> unsigned int nr_levels;
>
> - if (!em)
> + if (!em || em_is_artificial(em))
> return false;
>
> policy = cpufreq_cdev->policy;
> diff --git a/drivers/thermal/devfreq_cooling.c b/drivers/thermal/devfreq_cooling.c
> index 4310cb342a9f..b04dcbbf721a 100644
> --- a/drivers/thermal/devfreq_cooling.c
> +++ b/drivers/thermal/devfreq_cooling.c
> @@ -358,6 +358,7 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
> struct thermal_cooling_device *cdev;
> struct device *dev = df->dev.parent;
> struct devfreq_cooling_device *dfc;
> + struct em_perf_domain *em;
> char *name;
> int err, num_opps;
>
> @@ -367,8 +368,9 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
>
> dfc->devfreq = df;
>
> - dfc->em_pd = em_pd_get(dev);
> - if (dfc->em_pd) {
> + em = em_pd_get(dev);
> + if (em && !em_is_artificial(em)) {
> + dfc->em_pd = em;
> devfreq_cooling_ops.get_requested_power =
> devfreq_cooling_get_requested_power;
> devfreq_cooling_ops.state2power = devfreq_cooling_state2power;
> @@ -379,7 +381,7 @@ of_devfreq_cooling_register_power(struct device_node *np, struct devfreq *df,
> num_opps = em_pd_nr_perf_states(dfc->em_pd);
> } else {
> /* Backward compatibility for drivers which do not use IPA */
> - dev_dbg(dev, "missing EM for cooling device\n");
> + dev_dbg(dev, "missing proper EM for cooling device\n");
>
> num_opps = dev_pm_opp_get_opp_count(dev);

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

--
viresh

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