| Message ID | 20190811212315.12689-19-digetx@gmail.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
| Series | More improvements for Tegra30 devfreq driver | expand |
Hi, On 19. 8. 12. 오전 6:23, 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@gmail.com> > --- > drivers/devfreq/tegra30-devfreq.c | 71 ++++++++++++++++++++++--------- > 1 file changed, 50 insertions(+), 21 deletions(-) > > diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c > index 8adc0ff48b45..e30314bd571a 100644 > --- a/drivers/devfreq/tegra30-devfreq.c > +++ b/drivers/devfreq/tegra30-devfreq.c > @@ -12,6 +12,7 @@ > #include <linux/interrupt.h> > #include <linux/io.h> > #include <linux/irq.h> > +#include <linux/jiffies.h> > #include <linux/module.h> > #include <linux/of_device.h> > #include <linux/platform_device.h> > @@ -236,7 +237,7 @@ tegra_actmon_dev_avg_dependency_freq(struct tegra_devfreq *tegra, > struct tegra_devfreq_device *dev) > { > return dev->config->avg_dependency_threshold / > - ACTMON_SAMPLING_PERIOD; > + tegra->devfreq->profile->polling_ms; > } > > static unsigned long > @@ -314,8 +315,8 @@ static void tegra_actmon_get_lower_upper(struct tegra_devfreq *tegra, > */ > *upper = tegra_actmon_account_cpu_freq(tegra, dev, *upper); > > - *lower *= ACTMON_SAMPLING_PERIOD; > - *upper *= ACTMON_SAMPLING_PERIOD; > + *lower *= tegra->devfreq->profile->polling_ms; > + *upper *= tegra->devfreq->profile->polling_ms; > } > > static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra, > @@ -341,8 +342,8 @@ static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra, > * result, but this one is probably the least churning, although > * it may look a bit convoluted. > */ > - if (freq * ACTMON_SAMPLING_PERIOD > upper) > - upper = freq * ACTMON_SAMPLING_PERIOD; > + if (freq * tegra->devfreq->profile->polling_ms > upper) > + upper = freq * tegra->devfreq->profile->polling_ms; > > /* > * We want to get interrupts when MCCPU client crosses the > @@ -420,7 +421,7 @@ static void actmon_isr_device(struct tegra_devfreq *tegra, > avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT); > dev_ctrl = device_readl(dev, ACTMON_DEV_CTRL); > > - dev->avg_freq = avg_count / ACTMON_SAMPLING_PERIOD; > + dev->avg_freq = avg_count / tegra->devfreq->profile->polling_ms; > > avg_intr_mask = ACTMON_DEV_INTR_AVG_BELOW_WMARK | > ACTMON_DEV_INTR_AVG_ABOVE_WMARK; > @@ -499,7 +500,7 @@ static unsigned long actmon_update_target(struct tegra_devfreq *tegra, > * outdated. > */ > avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT); > - avg_freq = avg_count / ACTMON_SAMPLING_PERIOD; > + avg_freq = avg_count / tegra->devfreq->profile->polling_ms; > > old_upper = tegra_actmon_upper_freq(tegra, dev->avg_freq); > new_upper = tegra_actmon_upper_freq(tegra, avg_freq); > @@ -675,7 +676,7 @@ static int tegra_actmon_cpu_notify_cb(struct notifier_block *nb, > * here for too long, otherwise CPUFreq's core will complain with a > * warning splat. > */ > - delay = msecs_to_jiffies(ACTMON_SAMPLING_PERIOD); > + delay = msecs_to_jiffies(tegra->devfreq->profile->polling_ms); > schedule_delayed_work(&tegra->cpufreq_update_work, delay); > > return NOTIFY_OK; > @@ -690,7 +691,7 @@ static void tegra_actmon_configure_device(struct tegra_devfreq *tegra, > dev->boost_freq = 0; > > dev->avg_freq = clk_get_rate(tegra->emc_clock) / KHZ; > - device_writel(dev, dev->avg_freq * ACTMON_SAMPLING_PERIOD, > + device_writel(dev, dev->avg_freq * tegra->devfreq->profile->polling_ms, > ACTMON_DEV_INIT_AVG); > > tegra_devfreq_update_avg_wmark(tegra, dev, dev->avg_freq); > @@ -725,7 +726,14 @@ static int tegra_actmon_start(struct tegra_devfreq *tegra) > unsigned int i; > int err; > > - actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1, > + if (!tegra->devfreq->stop_polling) I don't prefer to change the 'stop_polling' on each device driver direclty without devfreq interface. Don't access it directly. > + return 0; > + > + tegra->devfreq->previous_freq = clk_get_rate(tegra->emc_clock) / KHZ; > + tegra->devfreq->last_stat_updated = jiffies; > + tegra->devfreq->stop_polling = false; ditto. > + > + actmon_writel(tegra, tegra->devfreq->profile->polling_ms - 1, > ACTMON_GLB_PERIOD_CTRL); > > /* > @@ -776,6 +784,11 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra) > { > unsigned int i; > > + if (tegra->devfreq->stop_polling) ditto. > + return; > + > + mutex_unlock(&tegra->devfreq->lock); > + > disable_irq(tegra->irq); > > cpufreq_unregister_notifier(&tegra->cpu_rate_change_nb, > @@ -783,10 +796,16 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra) > > cancel_delayed_work_sync(&tegra->cpufreq_update_work); > > + mutex_lock(&tegra->devfreq->lock); > + > for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) > tegra_actmon_stop_device(&tegra->devices[i]); > > clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb); > + > + devfreq_update_status(tegra->devfreq, tegra->devfreq->previous_freq); > + > + tegra->devfreq->stop_polling = true; ditto. > } > > static int tegra_devfreq_target(struct device *dev, unsigned long *freq, > @@ -846,7 +865,7 @@ 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 = cur_freq * ACTMON_SAMPLING_PERIOD; > + stat->total_time = cur_freq * tegra->devfreq->profile->polling_ms; > > stat->busy_time = min(stat->busy_time, stat->total_time); > > @@ -854,7 +873,7 @@ 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, > }; > @@ -895,8 +914,11 @@ 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, *delay_ptr = data; > int ret = 0; > > + mutex_lock(&devfreq->lock); > + > /* > * Couple device with the governor early as it is needed at > * the moment of governor's start (used by ISR). > @@ -905,26 +927,33 @@ static int tegra_governor_event_handler(struct devfreq *devfreq, > > switch (event) { > case DEVFREQ_GOV_START: > - devfreq_monitor_start(devfreq); > + devfreq->stop_polling = true; It is not proper to initialize the 'stop_polling' on device driver directly. > + /* fall through */ > + case DEVFREQ_GOV_RESUME: > ret = tegra_actmon_start(tegra); > break; > > case DEVFREQ_GOV_STOP: > - tegra_actmon_stop(tegra); > - devfreq_monitor_stop(devfreq); Why do you remove them? > - break; > - > + /* fall through */ > case DEVFREQ_GOV_SUSPEND: > tegra_actmon_stop(tegra); > - devfreq_monitor_suspend(devfreq); Why do you remove it? > break; > > - case DEVFREQ_GOV_RESUME: > - devfreq_monitor_resume(devfreq); > - ret = tegra_actmon_start(tegra); > + case DEVFREQ_GOV_INTERVAL: > + new_delay = *delay_ptr; > + > + if (!new_delay || new_delay > 256) { > + ret = -EINVAL; > + } else { > + tegra_actmon_stop(tegra); > + devfreq->profile->polling_ms = new_delay; > + ret = tegra_actmon_start(tegra); > + } > break; > } > > + mutex_unlock(&devfreq->lock); > + > return ret; > } > >
02.10.2019 03:18, Chanwoo Choi пишет: > Hi, > > On 19. 8. 12. 오전 6:23, 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@gmail.com> >> --- >> drivers/devfreq/tegra30-devfreq.c | 71 ++++++++++++++++++++++--------- >> 1 file changed, 50 insertions(+), 21 deletions(-) >> >> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c >> index 8adc0ff48b45..e30314bd571a 100644 >> --- a/drivers/devfreq/tegra30-devfreq.c >> +++ b/drivers/devfreq/tegra30-devfreq.c >> @@ -12,6 +12,7 @@ >> #include <linux/interrupt.h> >> #include <linux/io.h> >> #include <linux/irq.h> >> +#include <linux/jiffies.h> >> #include <linux/module.h> >> #include <linux/of_device.h> >> #include <linux/platform_device.h> >> @@ -236,7 +237,7 @@ tegra_actmon_dev_avg_dependency_freq(struct tegra_devfreq *tegra, >> struct tegra_devfreq_device *dev) >> { >> return dev->config->avg_dependency_threshold / >> - ACTMON_SAMPLING_PERIOD; >> + tegra->devfreq->profile->polling_ms; >> } >> >> static unsigned long >> @@ -314,8 +315,8 @@ static void tegra_actmon_get_lower_upper(struct tegra_devfreq *tegra, >> */ >> *upper = tegra_actmon_account_cpu_freq(tegra, dev, *upper); >> >> - *lower *= ACTMON_SAMPLING_PERIOD; >> - *upper *= ACTMON_SAMPLING_PERIOD; >> + *lower *= tegra->devfreq->profile->polling_ms; >> + *upper *= tegra->devfreq->profile->polling_ms; >> } >> >> static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra, >> @@ -341,8 +342,8 @@ static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra, >> * result, but this one is probably the least churning, although >> * it may look a bit convoluted. >> */ >> - if (freq * ACTMON_SAMPLING_PERIOD > upper) >> - upper = freq * ACTMON_SAMPLING_PERIOD; >> + if (freq * tegra->devfreq->profile->polling_ms > upper) >> + upper = freq * tegra->devfreq->profile->polling_ms; >> >> /* >> * We want to get interrupts when MCCPU client crosses the >> @@ -420,7 +421,7 @@ static void actmon_isr_device(struct tegra_devfreq *tegra, >> avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT); >> dev_ctrl = device_readl(dev, ACTMON_DEV_CTRL); >> >> - dev->avg_freq = avg_count / ACTMON_SAMPLING_PERIOD; >> + dev->avg_freq = avg_count / tegra->devfreq->profile->polling_ms; >> >> avg_intr_mask = ACTMON_DEV_INTR_AVG_BELOW_WMARK | >> ACTMON_DEV_INTR_AVG_ABOVE_WMARK; >> @@ -499,7 +500,7 @@ static unsigned long actmon_update_target(struct tegra_devfreq *tegra, >> * outdated. >> */ >> avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT); >> - avg_freq = avg_count / ACTMON_SAMPLING_PERIOD; >> + avg_freq = avg_count / tegra->devfreq->profile->polling_ms; >> >> old_upper = tegra_actmon_upper_freq(tegra, dev->avg_freq); >> new_upper = tegra_actmon_upper_freq(tegra, avg_freq); >> @@ -675,7 +676,7 @@ static int tegra_actmon_cpu_notify_cb(struct notifier_block *nb, >> * here for too long, otherwise CPUFreq's core will complain with a >> * warning splat. >> */ >> - delay = msecs_to_jiffies(ACTMON_SAMPLING_PERIOD); >> + delay = msecs_to_jiffies(tegra->devfreq->profile->polling_ms); >> schedule_delayed_work(&tegra->cpufreq_update_work, delay); >> >> return NOTIFY_OK; >> @@ -690,7 +691,7 @@ static void tegra_actmon_configure_device(struct tegra_devfreq *tegra, >> dev->boost_freq = 0; >> >> dev->avg_freq = clk_get_rate(tegra->emc_clock) / KHZ; >> - device_writel(dev, dev->avg_freq * ACTMON_SAMPLING_PERIOD, >> + device_writel(dev, dev->avg_freq * tegra->devfreq->profile->polling_ms, >> ACTMON_DEV_INIT_AVG); >> >> tegra_devfreq_update_avg_wmark(tegra, dev, dev->avg_freq); >> @@ -725,7 +726,14 @@ static int tegra_actmon_start(struct tegra_devfreq *tegra) >> unsigned int i; >> int err; >> >> - actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1, >> + if (!tegra->devfreq->stop_polling) > > I don't prefer to change the 'stop_polling' on each device driver direclty > without devfreq interface. Don't access it directly. Hmm.. okay. Please see more comments below. >> + return 0; >> + >> + tegra->devfreq->previous_freq = clk_get_rate(tegra->emc_clock) / KHZ; >> + tegra->devfreq->last_stat_updated = jiffies; >> + tegra->devfreq->stop_polling = false; > > ditto. > >> + >> + actmon_writel(tegra, tegra->devfreq->profile->polling_ms - 1, >> ACTMON_GLB_PERIOD_CTRL); >> >> /* >> @@ -776,6 +784,11 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra) >> { >> unsigned int i; >> >> + if (tegra->devfreq->stop_polling) > > ditto. > >> + return; >> + >> + mutex_unlock(&tegra->devfreq->lock); >> + >> disable_irq(tegra->irq); >> >> cpufreq_unregister_notifier(&tegra->cpu_rate_change_nb, >> @@ -783,10 +796,16 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra) >> >> cancel_delayed_work_sync(&tegra->cpufreq_update_work); >> >> + mutex_lock(&tegra->devfreq->lock); >> + >> for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) >> tegra_actmon_stop_device(&tegra->devices[i]); >> >> clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb); >> + >> + devfreq_update_status(tegra->devfreq, tegra->devfreq->previous_freq); >> + >> + tegra->devfreq->stop_polling = true; > > ditto. > >> } >> >> static int tegra_devfreq_target(struct device *dev, unsigned long *freq, >> @@ -846,7 +865,7 @@ 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 = cur_freq * ACTMON_SAMPLING_PERIOD; >> + stat->total_time = cur_freq * tegra->devfreq->profile->polling_ms; >> >> stat->busy_time = min(stat->busy_time, stat->total_time); >> >> @@ -854,7 +873,7 @@ 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, >> }; >> @@ -895,8 +914,11 @@ 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, *delay_ptr = data; >> int ret = 0; >> >> + mutex_lock(&devfreq->lock); >> + >> /* >> * Couple device with the governor early as it is needed at >> * the moment of governor's start (used by ISR). >> @@ -905,26 +927,33 @@ static int tegra_governor_event_handler(struct devfreq *devfreq, >> >> switch (event) { >> case DEVFREQ_GOV_START: >> - devfreq_monitor_start(devfreq); >> + devfreq->stop_polling = true; > > It is not proper to initialize the 'stop_polling' on device driver directly. > >> + /* fall through */ >> + case DEVFREQ_GOV_RESUME: >> ret = tegra_actmon_start(tegra); >> break; >> >> case DEVFREQ_GOV_STOP: >> - tegra_actmon_stop(tegra); >> - devfreq_monitor_stop(devfreq); > > Why do you remove them? Becasue DEVFREQ_GOV_STOP and DEVFREQ_GOV_SUSPEND are doing the same now: case DEVFREQ_GOV_STOP: /* fall through */ case DEVFREQ_GOV_SUSPEND: tegra_actmon_stop(tegra); break; >> - break; >> - >> + /* fall through */ >> case DEVFREQ_GOV_SUSPEND: >> tegra_actmon_stop(tegra); >> - devfreq_monitor_suspend(devfreq); > > Why do you remove it? a) it takes the same mutex devfreq->lock as tegra_governor_event_handler() b) the devfreq's manual polling isn't needed for this driver and thus devfreq->work is unwanted c) this patch makes tegra_actmon_stop() to replicate what devfreq_monitor_suspend() does It looks like it will be better to add new generic events for the governors, like DEVFREQ_GOV_START/STOP_POLLING. Then this driver will be able to customize start/stop of the polling, while software governors will utilize some new default helpers that will start/stop the polling work. What do you think? [snip]
diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c index 8adc0ff48b45..e30314bd571a 100644 --- a/drivers/devfreq/tegra30-devfreq.c +++ b/drivers/devfreq/tegra30-devfreq.c @@ -12,6 +12,7 @@ #include <linux/interrupt.h> #include <linux/io.h> #include <linux/irq.h> +#include <linux/jiffies.h> #include <linux/module.h> #include <linux/of_device.h> #include <linux/platform_device.h> @@ -236,7 +237,7 @@ tegra_actmon_dev_avg_dependency_freq(struct tegra_devfreq *tegra, struct tegra_devfreq_device *dev) { return dev->config->avg_dependency_threshold / - ACTMON_SAMPLING_PERIOD; + tegra->devfreq->profile->polling_ms; } static unsigned long @@ -314,8 +315,8 @@ static void tegra_actmon_get_lower_upper(struct tegra_devfreq *tegra, */ *upper = tegra_actmon_account_cpu_freq(tegra, dev, *upper); - *lower *= ACTMON_SAMPLING_PERIOD; - *upper *= ACTMON_SAMPLING_PERIOD; + *lower *= tegra->devfreq->profile->polling_ms; + *upper *= tegra->devfreq->profile->polling_ms; } static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra, @@ -341,8 +342,8 @@ static void tegra_devfreq_update_avg_wmark(struct tegra_devfreq *tegra, * result, but this one is probably the least churning, although * it may look a bit convoluted. */ - if (freq * ACTMON_SAMPLING_PERIOD > upper) - upper = freq * ACTMON_SAMPLING_PERIOD; + if (freq * tegra->devfreq->profile->polling_ms > upper) + upper = freq * tegra->devfreq->profile->polling_ms; /* * We want to get interrupts when MCCPU client crosses the @@ -420,7 +421,7 @@ static void actmon_isr_device(struct tegra_devfreq *tegra, avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT); dev_ctrl = device_readl(dev, ACTMON_DEV_CTRL); - dev->avg_freq = avg_count / ACTMON_SAMPLING_PERIOD; + dev->avg_freq = avg_count / tegra->devfreq->profile->polling_ms; avg_intr_mask = ACTMON_DEV_INTR_AVG_BELOW_WMARK | ACTMON_DEV_INTR_AVG_ABOVE_WMARK; @@ -499,7 +500,7 @@ static unsigned long actmon_update_target(struct tegra_devfreq *tegra, * outdated. */ avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT); - avg_freq = avg_count / ACTMON_SAMPLING_PERIOD; + avg_freq = avg_count / tegra->devfreq->profile->polling_ms; old_upper = tegra_actmon_upper_freq(tegra, dev->avg_freq); new_upper = tegra_actmon_upper_freq(tegra, avg_freq); @@ -675,7 +676,7 @@ static int tegra_actmon_cpu_notify_cb(struct notifier_block *nb, * here for too long, otherwise CPUFreq's core will complain with a * warning splat. */ - delay = msecs_to_jiffies(ACTMON_SAMPLING_PERIOD); + delay = msecs_to_jiffies(tegra->devfreq->profile->polling_ms); schedule_delayed_work(&tegra->cpufreq_update_work, delay); return NOTIFY_OK; @@ -690,7 +691,7 @@ static void tegra_actmon_configure_device(struct tegra_devfreq *tegra, dev->boost_freq = 0; dev->avg_freq = clk_get_rate(tegra->emc_clock) / KHZ; - device_writel(dev, dev->avg_freq * ACTMON_SAMPLING_PERIOD, + device_writel(dev, dev->avg_freq * tegra->devfreq->profile->polling_ms, ACTMON_DEV_INIT_AVG); tegra_devfreq_update_avg_wmark(tegra, dev, dev->avg_freq); @@ -725,7 +726,14 @@ static int tegra_actmon_start(struct tegra_devfreq *tegra) unsigned int i; int err; - actmon_writel(tegra, ACTMON_SAMPLING_PERIOD - 1, + if (!tegra->devfreq->stop_polling) + return 0; + + tegra->devfreq->previous_freq = clk_get_rate(tegra->emc_clock) / KHZ; + tegra->devfreq->last_stat_updated = jiffies; + tegra->devfreq->stop_polling = false; + + actmon_writel(tegra, tegra->devfreq->profile->polling_ms - 1, ACTMON_GLB_PERIOD_CTRL); /* @@ -776,6 +784,11 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra) { unsigned int i; + if (tegra->devfreq->stop_polling) + return; + + mutex_unlock(&tegra->devfreq->lock); + disable_irq(tegra->irq); cpufreq_unregister_notifier(&tegra->cpu_rate_change_nb, @@ -783,10 +796,16 @@ static void tegra_actmon_stop(struct tegra_devfreq *tegra) cancel_delayed_work_sync(&tegra->cpufreq_update_work); + mutex_lock(&tegra->devfreq->lock); + for (i = 0; i < ARRAY_SIZE(tegra->devices); i++) tegra_actmon_stop_device(&tegra->devices[i]); clk_notifier_unregister(tegra->emc_clock, &tegra->clk_rate_change_nb); + + devfreq_update_status(tegra->devfreq, tegra->devfreq->previous_freq); + + tegra->devfreq->stop_polling = true; } static int tegra_devfreq_target(struct device *dev, unsigned long *freq, @@ -846,7 +865,7 @@ 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 = cur_freq * ACTMON_SAMPLING_PERIOD; + stat->total_time = cur_freq * tegra->devfreq->profile->polling_ms; stat->busy_time = min(stat->busy_time, stat->total_time); @@ -854,7 +873,7 @@ 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, }; @@ -895,8 +914,11 @@ 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, *delay_ptr = data; int ret = 0; + mutex_lock(&devfreq->lock); + /* * Couple device with the governor early as it is needed at * the moment of governor's start (used by ISR). @@ -905,26 +927,33 @@ static int tegra_governor_event_handler(struct devfreq *devfreq, switch (event) { case DEVFREQ_GOV_START: - devfreq_monitor_start(devfreq); + devfreq->stop_polling = true; + /* fall through */ + case DEVFREQ_GOV_RESUME: ret = tegra_actmon_start(tegra); break; case DEVFREQ_GOV_STOP: - tegra_actmon_stop(tegra); - devfreq_monitor_stop(devfreq); - break; - + /* fall through */ case DEVFREQ_GOV_SUSPEND: tegra_actmon_stop(tegra); - devfreq_monitor_suspend(devfreq); break; - case DEVFREQ_GOV_RESUME: - devfreq_monitor_resume(devfreq); - ret = tegra_actmon_start(tegra); + case DEVFREQ_GOV_INTERVAL: + new_delay = *delay_ptr; + + if (!new_delay || new_delay > 256) { + ret = -EINVAL; + } else { + tegra_actmon_stop(tegra); + devfreq->profile->polling_ms = new_delay; + ret = tegra_actmon_start(tegra); + } break; } + mutex_unlock(&devfreq->lock); + return ret; }
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@gmail.com> --- drivers/devfreq/tegra30-devfreq.c | 71 ++++++++++++++++++++++--------- 1 file changed, 50 insertions(+), 21 deletions(-)