Re: [PATCH v4 19/24] PM / devfreq: tegra30: Optimize upper consecutive watermark selection

Chanwoo Choi
2019-07-18T09:48:07Z

On 19. 7. 8. 오전 7:32, Dmitry Osipenko wrote:
> The memory activity counter may get a bit higher than a watermark which
> is selected based on OPP that corresponds to a highest EMC rate, in this
> case watermark is lower than the actual memory activity is and thus
> results in unwanted "upper" interrupts.
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> drivers/devfreq/tegra30-devfreq.c | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)

It seems that you can combine patch19 with patch20.

>
> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> index 8d6bf6e9f1ae..c3cf87231d25 100644
> --- a/drivers/devfreq/tegra30-devfreq.c
> +++ b/drivers/devfreq/tegra30-devfreq.c
> @@ -363,7 +363,18 @@ static void tegra_devfreq_update_wmark(struct tegra_devfreq *tegra,
> tegra_actmon_get_lower_upper(tegra, dev, freq - 1, &lower, &upper);
>
> delta = do_percent(upper - lower, dev->config->boost_up_threshold);
> - device_writel(dev, lower + delta, ACTMON_DEV_UPPER_WMARK);
> +
> + /*
> + * The memory events count could go a bit higher than the maximum
> + * defined by the OPPs, hence make the upper watermark infinitely
> + * high to avoid unnecessary upper interrupts in that case.
> + */
> + if (freq == tegra->max_freq)
> + upper = ULONG_MAX;
> + else
> + upper = lower + delta;
> +
> + device_writel(dev, upper, ACTMON_DEV_UPPER_WMARK);
>
> /*
> * Meanwhile the lower mark is based on the average value
>

--
Best Regards,
Chanwoo Choi
Samsung Electronics