On 19. 11. 5. 오전 6:56, Dmitry Osipenko wrote:
> The dependency threshold designates a memory activity level below which
> CPU's frequency isn't accounted. Currently the threshold is given in
> "memory cycle" units and that value depends on the polling interval which
> is fixed to 12ms in the driver. Later on we'd want to add support for a
> variable polling interval and thus the threshold value either needs to be
> scaled in accordance to the polling interval or it needs to be represented
> in a units that do not depend on the polling interval.
>
> It is nicer to have threshold value being defined independently of the
> polling interval, thus this patch converts the dependency threshold units
> from "cycle" to "kHz". Having this change as a separate-preparatory patch
> will make easier to follow further patches.
>
> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> ---
> drivers/devfreq/tegra30-devfreq.c | 30 +++++++++++++++++-------------
> 1 file changed, 17 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> index 852bde6249c7..3bd920829bfd 100644
> --- a/drivers/devfreq/tegra30-devfreq.c
> +++ b/drivers/devfreq/tegra30-devfreq.c
> @@ -96,9 +96,10 @@ struct tegra_devfreq_device_config {
> unsigned int boost_down_threshold;
>
> /*
> - * Threshold of activity (cycles) below which the CPU frequency isn't
> - * to be taken into account. This is to avoid increasing the EMC
> - * frequency when the CPU is very busy but not accessing the bus often.
> + * Threshold of activity (cycles translated to kHz) below which the
> + * CPU frequency isn't to be taken into account. This is to avoid
> + * increasing the EMC frequency when the CPU is very busy but not
> + * accessing the bus often.
> */
> u32 avg_dependency_threshold;
> };
> @@ -126,7 +127,7 @@ static const struct tegra_devfreq_device_config actmon_device_configs[] = {
> .boost_down_coeff = 90,
> .boost_up_threshold = 27,
> .boost_down_threshold = 10,
> - .avg_dependency_threshold = 50000,
> + .avg_dependency_threshold = 16000, /* 16MHz in kHz units */
> },
> };
>
> @@ -311,7 +312,6 @@ static unsigned long actmon_device_target_freq(struct tegra_devfreq *tegra,
> target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD;
> avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold;
> target_freq = do_percent(target_freq, avg_sustain_coef);
> - target_freq += dev->boost_freq;
>
> return target_freq;
> }
> @@ -322,15 +322,18 @@ static void actmon_update_target(struct tegra_devfreq *tegra,
> unsigned long cpu_freq = 0;
> unsigned long static_cpu_emc_freq = 0;
>
> - if (dev->config->avg_dependency_threshold) {
> + dev->target_freq = actmon_device_target_freq(tegra, dev);
> +
> + if (dev->config->avg_dependency_threshold &&
> + dev->config->avg_dependency_threshold <= dev->target_freq) {
> cpu_freq = cpufreq_quick_get(0);
> static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq);
> - }
>
> - dev->target_freq = actmon_device_target_freq(tegra, dev);
> -
> - if (dev->avg_count >= dev->config->avg_dependency_threshold)
> + dev->target_freq += dev->boost_freq;
> dev->target_freq = max(dev->target_freq, static_cpu_emc_freq);
> + } else {
> + dev->target_freq += dev->boost_freq;
> + }
> }
>
> static irqreturn_t actmon_thread_isr(int irq, void *data)
> @@ -396,15 +399,16 @@ static unsigned long
> tegra_actmon_cpufreq_contribution(struct tegra_devfreq *tegra,
> unsigned int cpu_freq)
> {
> + struct tegra_devfreq_device *actmon_dev = &tegra->devices[MCCPU];
> unsigned long static_cpu_emc_freq, dev_freq;
>
> + dev_freq = actmon_device_target_freq(tegra, actmon_dev);
> +
> /* check whether CPU's freq is taken into account at all */
> - if (tegra->devices[MCCPU].avg_count <
> - tegra->devices[MCCPU].config->avg_dependency_threshold)
> + if (dev_freq < actmon_dev->config->avg_dependency_threshold)
> return 0;
>
> static_cpu_emc_freq = actmon_cpu_to_emc_rate(tegra, cpu_freq);
> - dev_freq = actmon_device_target_freq(tegra, &tegra->devices[MCCPU]);
>
> if (dev_freq >= static_cpu_emc_freq)
> return 0;
>
Reviewed-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
--
Best Regards,
Chanwoo Choi
Samsung Electronics
