From: Chanwoo Choi <cw00.choi@samsung.com>
To: Dmitry Osipenko <digetx@gmail.com>,
Thierry Reding <thierry.reding@gmail.com>,
MyungJoo Ham <myungjoo.ham@samsung.com>,
Kyungmin Park <kyungmin.park@samsung.com>,
Jonathan Hunter <jonathanh@nvidia.com>,
Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v6 08/19] PM / devfreq: tegra30: Ensure that target freq won't overflow
Date: Tue, 20 Aug 2019 09:23:23 +0900 [thread overview]
Message-ID: <c85dbd27-7536-9c51-19a2-fe1c2c6342b9@samsung.com> (raw)
In-Reply-To: <20190811212315.12689-9-digetx@gmail.com>
On 19. 8. 12. 오전 6:23, Dmitry Osipenko wrote:
> We already had few integer overflow bugs, let's limit the freq for
> consistency.
>
> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
> ---
> drivers/devfreq/tegra30-devfreq.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/devfreq/tegra30-devfreq.c b/drivers/devfreq/tegra30-devfreq.c
> index 70dce58212a4..ca499368ee81 100644
> --- a/drivers/devfreq/tegra30-devfreq.c
> +++ b/drivers/devfreq/tegra30-devfreq.c
> @@ -430,7 +430,7 @@ static unsigned long actmon_update_target(struct tegra_devfreq *tegra,
> target_freq = dev->avg_count / ACTMON_SAMPLING_PERIOD + dev->boost_freq;
> target_freq = tegra_actmon_account_cpu_freq(tegra, dev, target_freq);
>
> - return target_freq;
> + return min(target_freq, tegra->max_freq);
Once again, did you meet this case sometimes?
Usually, we can prevent the overflow of target_freq
when calculating the target frequency or this style.
I think that if the overflow of target frequency happen frequently,
it might have the problem of calculation way.
> }
>
> static irqreturn_t actmon_thread_isr(int irq, void *data)
>
--
Best Regards,
Chanwoo Choi
Samsung Electronics
next prev parent reply other threads:[~2019-08-20 0:19 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-11 21:22 [PATCH v6 00/19] More improvements for Tegra30 devfreq driver Dmitry Osipenko
2019-08-11 21:22 ` [PATCH v6 01/19] PM / devfreq: tegra30: Change irq type to unsigned int Dmitry Osipenko
2019-08-11 21:22 ` [PATCH v6 02/19] PM / devfreq: tegra30: Keep interrupt disabled while governor is stopped Dmitry Osipenko
2019-08-20 0:02 ` Chanwoo Choi
2019-08-11 21:22 ` [PATCH v6 03/19] PM / devfreq: tegra30: Handle possible round-rate error Dmitry Osipenko
2019-08-20 0:06 ` Chanwoo Choi
2019-08-11 21:23 ` [PATCH v6 04/19] PM / devfreq: tegra30: Drop write-barrier Dmitry Osipenko
2019-08-11 21:23 ` [PATCH v6 05/19] PM / devfreq: tegra30: Set up watermarks properly Dmitry Osipenko
2019-08-11 21:23 ` [PATCH v6 06/19] PM / devfreq: tegra30: Tune up boosting thresholds Dmitry Osipenko
2019-08-11 21:23 ` [PATCH v6 07/19] PM / devfreq: tegra30: Fix integer overflow on CPU's freq max out Dmitry Osipenko
2019-08-11 21:23 ` [PATCH v6 08/19] PM / devfreq: tegra30: Ensure that target freq won't overflow Dmitry Osipenko
2019-08-20 0:23 ` Chanwoo Choi [this message]
2019-08-20 23:19 ` Dmitry Osipenko
2019-08-11 21:23 ` [PATCH v6 09/19] PM / devfreq: tegra30: Use kHz units uniformly in the code Dmitry Osipenko
2019-10-01 23:29 ` Chanwoo Choi
2019-10-02 18:26 ` Dmitry Osipenko
2019-08-11 21:23 ` [PATCH v6 10/19] PM / devfreq: tegra30: Reduce unnecessary interrupts activity Dmitry Osipenko
2019-10-01 23:35 ` Chanwoo Choi
2019-10-02 18:40 ` Dmitry Osipenko
2019-08-11 21:23 ` [PATCH v6 11/19] PM / devfreq: tegra30: Use CPUFreq notifier Dmitry Osipenko
2019-10-02 0:02 ` Chanwoo Choi
2019-10-02 14:06 ` Dmitry Osipenko
2019-08-11 21:23 ` [PATCH v6 12/19] PM / devfreq: tegra30: Move clk-notifier's registration to governor's start Dmitry Osipenko
2019-08-11 21:23 ` [PATCH v6 13/19] PM / devfreq: tegra30: Reset boosting on startup Dmitry Osipenko
2019-08-11 21:23 ` [PATCH v6 14/19] PM / devfreq: tegra30: Don't enable consecutive-down interrupt " Dmitry Osipenko
2019-10-02 0:04 ` Chanwoo Choi
2019-08-11 21:23 ` [PATCH v6 15/19] PM / devfreq: tegra30: Constify structs Dmitry Osipenko
2019-08-11 21:23 ` [PATCH v6 16/19] PM / devfreq: tegra30: Include appropriate header Dmitry Osipenko
2019-08-11 21:23 ` [PATCH v6 17/19] PM / devfreq: tegra30: Increase sampling period to 16ms Dmitry Osipenko
2019-08-11 21:23 ` [PATCH v6 18/19] PM / devfreq: tegra30: Support variable polling interval Dmitry Osipenko
2019-10-02 0:18 ` Chanwoo Choi
2019-10-02 15:27 ` Dmitry Osipenko
2019-08-11 21:23 ` [PATCH v6 19/19] PM / devfreq: tegra20/30: Add Dmitry as a maintainer Dmitry Osipenko
2019-10-01 21:15 ` [PATCH v6 00/19] More improvements for Tegra30 devfreq driver Dmitry Osipenko
2019-10-02 0:25 ` Chanwoo Choi
2019-10-02 13:54 ` Dmitry Osipenko
2019-10-05 16:29 ` Peter Geis
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