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From: Lukasz Luba <lukasz.luba@arm.com>
To: Christian Loehle <christian.loehle@arm.com>
Cc: dietmar.eggemann@arm.com, linux-pm@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, sboyd@kernel.org,
	nm@ti.com, linux-samsung-soc@vger.kernel.org,
	daniel.lezcano@linaro.org, rafael@kernel.org,
	viresh.kumar@linaro.org, krzysztof.kozlowski@linaro.org,
	alim.akhtar@samsung.com, m.szyprowski@samsung.com,
	mhiramat@kernel.org
Subject: Re: [PATCH 3/4] PM: EM: Add em_dev_update_chip_binning()
Date: Fri, 22 Mar 2024 10:26:31 +0000	[thread overview]
Message-ID: <baa31f2d-98a9-4d37-a86e-e13ce7ab0081@arm.com> (raw)
In-Reply-To: <aefbb61c-8e15-4e40-9459-30bbbcb8d6f5@arm.com>

Hi Christian,

On 3/14/24 14:32, Christian Loehle wrote:
> On 14/03/2024 14:04, Lukasz Luba wrote:
>> Add a function which allows to modify easily the EM after the new voltage
>> information is available. The device drivers for the chip can adjust
>> the voltage values after setup. The voltage for the same frequency in OPP
>> can be different due to chip binning. The voltage impacts the power usage
>> and the EM power values can be updated to reflect that.
>>
>> Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
>> ---
>>   include/linux/energy_model.h |  5 ++++
>>   kernel/power/energy_model.c  | 51 ++++++++++++++++++++++++++++++++++++
>>   2 files changed, 56 insertions(+)
>>
>> diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h
>> index 770755df852f1..d30d67c2f07cf 100644
>> --- a/include/linux/energy_model.h
>> +++ b/include/linux/energy_model.h
>> @@ -172,6 +172,7 @@ struct em_perf_table __rcu *em_table_alloc(struct em_perf_domain *pd);
>>   void em_table_free(struct em_perf_table __rcu *table);
>>   int em_dev_compute_costs(struct device *dev, struct em_perf_state *table,
>>   			 int nr_states);
>> +int em_dev_update_chip_binning(struct device *dev);
>>   
>>   /**
>>    * em_pd_get_efficient_state() - Get an efficient performance state from the EM
>> @@ -387,6 +388,10 @@ int em_dev_compute_costs(struct device *dev, struct em_perf_state *table,
>>   {
>>   	return -EINVAL;
>>   }
>> +static inline int em_dev_update_chip_binning(struct device *dev)
>> +{
>> +	return -EINVAL;
>> +}
>>   #endif
>>   
>>   #endif
>> diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c
>> index 6960dd7393b2d..1494a909844a4 100644
>> --- a/kernel/power/energy_model.c
>> +++ b/kernel/power/energy_model.c
>> @@ -808,3 +808,54 @@ static void em_update_workfn(struct work_struct *work)
>>   {
>>   	em_check_capacity_update();
>>   }
>> +
>> +/**
>> + * em_dev_update_chip_binning() - Update Energy Model with new values after
>> + *			the new voltage information is present in the OPPs.
>> + * @dev		: Device for which the Energy Model has to be updated.
>> + *
>> + * This function allows to update easily the EM with new values available in
>> + * the OPP framework and DT. It can be used after the chip has been properly
>> + * verified by device drivers and the voltages adjusted for the 'chip binning'.
>> + * It uses the "dynamic-power-coefficient" DT property to calculate the power
>> + * values for EM. For power calculation it uses the new adjusted voltage
>> + * values known for OPPs, which might be changed after boot.
>> + */
>> +int em_dev_update_chip_binning(struct device *dev)
>> +{
>> +	struct em_perf_table __rcu *em_table;
>> +	struct em_perf_domain *pd;
>> +	int i, ret;
>> +
>> +	if (IS_ERR_OR_NULL(dev))
>> +		return -EINVAL;
>> +
>> +	pd = em_pd_get(dev);
>> +	if (!pd) {
>> +		dev_warn(dev, "Couldn't find Energy Model %d\n", ret);
> 
> ret is uninitialized at this point, I guess just
> +		dev_warn(dev, "Couldn't find Energy Model\n");
> already contains everything relevant.
> 

Good catch, thanks! Yes, I agree it contains enough. I'm going
to send v2 with this.

Regards,
Lukasz

  reply	other threads:[~2024-03-22 10:26 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-14 14:04 [PATCH 0/4] Update Energy Model after chip binning adjusted voltages Lukasz Luba
2024-03-14 14:04 ` [PATCH 1/4] OPP: OF: Export dev_opp_pm_calc_power() for usage from EM Lukasz Luba
2024-03-14 14:04 ` [PATCH 2/4] PM: EM: Change the em_adjust_new_capacity() to re-use code Lukasz Luba
2024-03-14 14:04 ` [PATCH 3/4] PM: EM: Add em_dev_update_chip_binning() Lukasz Luba
2024-03-14 14:32   ` Christian Loehle
2024-03-22 10:26     ` Lukasz Luba [this message]
2024-03-15 15:54   ` kernel test robot
2024-03-15 16:36   ` kernel test robot
2024-03-14 14:04 ` [PATCH 4/4] soc: samsung: exynos-asv: Update Energy Model after adjusting voltage Lukasz Luba

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