From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chanwoo Choi Subject: Re: [PATCH v4 19/24] PM / devfreq: tegra30: Optimize upper consecutive watermark selection Date: Thu, 18 Jul 2019 18:51:02 +0900 Message-ID: <17fabbaf-ceca-7551-0a58-9c8a0e7027ed@samsung.com> References: <20190707223303.6755-1-digetx@gmail.com> <20190707223303.6755-20-digetx@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190707223303.6755-20-digetx@gmail.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Osipenko , Thierry Reding , MyungJoo Ham , Kyungmin Park , Jonathan Hunter , Tomeu Vizoso Cc: linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-tegra@vger.kernel.org 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 > --- > 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