On 19. 7. 8. 오전 7:33, Dmitry Osipenko wrote: > The average count may get out of sync if interrupt was disabled / avoided > for a long time due to upper watermark optimization, hence it should be > re-synced on each target's update to ensure that watermarks are set up > correctly on EMC rate-change notification and that a correct frequency > is selected for device. > > Signed-off-by: Dmitry Osipenko <[email protected]> > --- > drivers/devfreq/tegra30-devfreq.c | 30 ++++++++++++++++++++++++++++++ > 1 file changed, 30 insertions(+) > > diff --git a/drivers/devfreq/tegra30-devfreq.c > b/drivers/devfreq/tegra30-devfreq.c > index 4d582809acb6..8a674fad26be 100644 > --- a/drivers/devfreq/tegra30-devfreq.c > +++ b/drivers/devfreq/tegra30-devfreq.c > @@ -466,11 +466,41 @@ static void actmon_isr_device(struct tegra_devfreq > *tegra, > dev->boost_freq, cpufreq_get(0)); > } > > +static void tegra_devfreq_sync_avg_count(struct tegra_devfreq *tegra, > + struct tegra_devfreq_device *dev) > +{ > + u32 avg_count, avg_freq, old_upper, new_upper; > + > + avg_count = device_readl(dev, ACTMON_DEV_AVG_COUNT); > + avg_freq = avg_count / ACTMON_SAMPLING_PERIOD; > + > + old_upper = tegra_actmon_upper_freq(tegra, dev->avg_freq); > + new_upper = tegra_actmon_upper_freq(tegra, avg_freq); > + > + /* similar to ISR, see comments in actmon_isr_device() */ > + if (old_upper != new_upper) { > + dev->avg_freq = avg_freq; > + dev->boost_freq = 0; > + } > +} > + > static unsigned long actmon_update_target(struct tegra_devfreq *tegra, > struct tegra_devfreq_device *dev) > { > unsigned long target_freq; > > + /* > + * The avg_count / avg_freq is getting snapshoted on device's > + * interrupt, but there are cases where actual value need to > + * be utilized on target's update, like CPUFreq boosting and > + * overriding the min freq via /sys/class/devfreq/devfreq0/min_freq > + * because we're optimizing the upper watermark based on the > + * actual EMC frequency. This means that interrupt may be > + * inactive for a long time and thus making snapshoted value > + * outdated. > + */ > + tegra_devfreq_sync_avg_count(tegra, dev);
I think that you don't need to add the separate function to calculate the 'dev->avg_freq'. It is enough with your detailed comment to add this code in this function. > + > target_freq = min(dev->avg_freq + dev->boost_freq, KHZ_MAX); > target_freq = tegra_actmon_account_cpu_freq(tegra, dev, target_freq); > > And also, is it impossible to squash this patch with patch19/patch20? -- Best Regards, Chanwoo Choi Samsung Electronics
