Hi Dmitry, On 19. 11. 5. 오전 6:56, Dmitry Osipenko wrote: > The ACTMON governor is interrupt-driven and currently hardware's polling > interval is fixed to 16ms in the driver. Devfreq supports variable polling > interval by the generic governors, let's re-use the generic interface for > changing of the polling interval. Now the polling interval can be changed > dynamically via /sys/class/devfreq/devfreq0/polling_interval. > > Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx> > --- > drivers/devfreq/tegra30-devfreq.c | 78 ++++++++++++++++++++++++++----- > 1 file changed, 66 insertions(+), 12 deletions(-) > > diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c > index 3bd920829bfd..e44f1a48f838 100644 > --- a/drivers/devfreq/tegra30-devfreq.c > +++ b/drivers/devfreq/tegra30-devfreq.c > @@ -171,6 +171,8 @@ struct tegra_devfreq { > struct tegra_devfreq_device devices[ARRAY_SIZE(actmon_device_configs)]; > > unsigned int irq; > + > + bool started; > }; > > struct tegra_actmon_emc_ratio { > @@ -209,18 +211,26 @@ static void device_writel(struct tegra_devfreq_device *dev, u32 val, > writel_relaxed(val, dev->regs + offset); > } > > -static unsigned long do_percent(unsigned long val, unsigned int pct) > +static unsigned long do_percent(unsigned long long val, unsigned int pct) > { > - return val * pct / 100; > + val = val * pct; > + do_div(val, 100); > + > + /* > + * High freq + high boosting percent + large polling interval are > + * resulting in integer overflow when watermarks are calculated. > + */ > + return min_t(u64, val, U32_MAX); > } > > static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra, > struct tegra_devfreq_device *dev) > { > - u32 avg = dev->avg_count; > u32 avg_band_freq = tegra->max_freq * ACTMON_DEFAULT_AVG_BAND / KHZ; > - u32 band = avg_band_freq * ACTMON_SAMPLING_PERIOD; > + u32 band = avg_band_freq * tegra->devfreq->profile->polling_ms; > + u32 avg; > > + avg = min(dev->avg_count, U32_MAX - band); > device_writel(dev, avg + band, ACTMON_DEV_AVG_UPPER_WMARK); > > avg = max(dev->avg_count, band); > @@ -230,7 +240,7 @@ static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra, > static void tegra_devfreq_update_wmark(struct tegra_devfreq *tegra, > struct tegra_devfreq_device *dev) > { > - u32 val = tegra->cur_freq * ACTMON_SAMPLING_PERIOD; > + u32 val = tegra->cur_freq * tegra->devfreq->profile->polling_ms; > > device_writel(dev, do_percent(val, dev->config->boost_up_threshold), > ACTMON_DEV_UPPER_WMARK); > @@ -309,7 +319,7 @@ static unsigned long actmon_device_target_freq(struct tegra_devfreq *tegra, > unsigned int avg_sustain_coef; > unsigned long target_freq; > > - target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD; > + target_freq = dev->avg_count / tegra->devfreq->profile->polling_ms; > avg_sustain_coef = 100 * 100 / dev->config->boost_up_threshold; > target_freq = do_percent(target_freq, avg_sustain_coef); > > @@ -469,7 +479,7 @@ static void tegra_actmon_configure_device(struct tegra_devfreq *tegra, > > dev->target_freq = tegra->cur_freq; > > - dev->avg_count = tegra->cur_freq * ACTMON_SAMPLING_PERIOD; > + dev->avg_count = tegra->cur_freq * tegra->devfreq->profile->polling_ms; > device_writel(dev, dev->avg_count, ACTMON_DEV_INIT_AVG); > > tegra_devfreq_update_avg_wmark(tegra, dev); > @@ -505,12 +515,15 @@ static void tegra_actmon_stop_devices(struct tegra_devfreq *tegra) > } > } > > -static int tegra_actmon_start(struct tegra_devfreq *tegra) > +static int tegra_actmon_resume(struct tegra_devfreq *tegra) > { > unsigned int i; > int err; > > - actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1, > + if (!tegra->devfreq->profile->polling_ms || !tegra->started) > + return 0; > + > + actmon_writel(tegra, tegra->devfreq->profile->polling_ms - 1, > ACTMON_GLB_PERIOD_CTRL); > > /* > @@ -558,8 +571,26 @@ static int tegra_actmon_start(struct tegra_devfreq *tegra) > return err; > } > > -static void tegra_actmon_stop(struct tegra_devfreq *tegra) > +static int tegra_actmon_start(struct tegra_devfreq *tegra) > { > + int ret = 0; > + > + if (!tegra->started) { > + tegra->started = true; > + > + ret = tegra_actmon_resume(tegra); > + if (ret) > + tegra->started = false; > + } > + > + return ret; > +} > + > +static void tegra_actmon_pause(struct tegra_devfreq *tegra) > +{ > + if (!tegra->devfreq->profile->polling_ms || !tegra->started) > + return; > + > disable_irq(tegra->irq); > > cpufreq_unregister_notifier(&tegra->cpu_rate_change_nb, > @@ -572,6 +603,12 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra) > clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb); > } > > +static void tegra_actmon_stop(struct tegra_devfreq *tegra) > +{ > + tegra_actmon_pause(tegra); > + tegra->started = false; > +} > + > static int tegra_devfreq_target(struct device *dev, unsigned long *freq, > u32 flags) > { > @@ -629,7 +666,7 @@ static int tegra_devfreq_get_dev_status(struct device *dev, > stat->busy_time *= 100 / BUS_SATURATION_RATIO; > > /* Number of cycles in a sampling period */ > - stat->total_time = ACTMON_SAMPLING_PERIOD * cur_freq; > + stat->total_time = tegra->devfreq->profile->polling_ms * cur_freq; > > stat->busy_time = min(stat->busy_time, stat->total_time); > > @@ -637,7 +674,7 @@ static int tegra_devfreq_get_dev_status(struct device *dev, > } > > static struct devfreq_dev_profile tegra_devfreq_profile = { > - .polling_ms = 0, > + .polling_ms = ACTMON_SAMPLING_PERIOD, > .target = tegra_devfreq_target, > .get_dev_status = tegra_devfreq_get_dev_status, > }; > @@ -677,6 +714,7 @@ static int tegra_governor_event_handler(struct devfreq *devfreq, > unsigned int event, void *data) > { > struct tegra_devfreq *tegra = dev_get_drvdata(devfreq->dev.parent); > + unsigned int *new_delay = data; > int ret = 0; > > /* > @@ -696,6 +734,21 @@ static int tegra_governor_event_handler(struct devfreq *devfreq, > devfreq_monitor_stop(devfreq); > break; > > + case DEVFREQ_GOV_INTERVAL: > + /* > + * ACTMON hardware supports up to 256 milliseconds for the > + * sampling period. > + */ > + if (*new_delay > 256) { > + ret = -EINVAL; > + break; > + } > + > + tegra_actmon_pause(tegra); > + devfreq_interval_update(devfreq, new_delay); > + ret = tegra_actmon_resume(tegra); > + break; > + > case DEVFREQ_GOV_SUSPEND: > tegra_actmon_stop(tegra); > devfreq_monitor_suspend(devfreq); > @@ -715,6 +768,7 @@ static struct devfreq_governor tegra_devfreq_governor = { > .get_target_freq = tegra_governor_get_target, > .event_handler = tegra_governor_event_handler, > .immutable = true, > + .interrupt_driven = true, > }; > > static int tegra_devfreq_probe(struct platform_device *pdev) > Reviewed-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx> -- Best Regards, Chanwoo Choi Samsung Electronics