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From: Dmitry Osipenko <digetx@gmail.com>
To: Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	MyungJoo Ham <myungjoo.ham@samsung.com>,
	Kyungmin Park <kyungmin.park@samsung.com>,
	Chanwoo Choi <cw00.choi@samsung.com>,
	Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: linux-pm@vger.kernel.org, linux-tegra@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v4 09/16] PM / devfreq: tegra: Avoid inconsistency of current frequency value
Date: Thu,  2 May 2019 02:38:08 +0300	[thread overview]
Message-ID: <20190501233815.32643-10-digetx@gmail.com> (raw)
Message-ID: <20190501233808.xtKENtEhmpxP1e4vZbZVl1TimKCmHc2L3n2GOAu3ltg@z> (raw)
In-Reply-To: <20190501233815.32643-1-digetx@gmail.com>

The frequency value potentially could change in-between. It doesn't
cause any real problem at all right now, but that could change in the
future. Hence let's avoid the inconsistency.

Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/devfreq/tegra-devfreq.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/devfreq/tegra-devfreq.c b/drivers/devfreq/tegra-devfreq.c
index ea0da05cd7f2..5265d735419f 100644
--- a/drivers/devfreq/tegra-devfreq.c
+++ b/drivers/devfreq/tegra-devfreq.c
@@ -509,13 +509,15 @@ static int tegra_devfreq_get_dev_status(struct device *dev,
 {
 	struct tegra_devfreq *tegra = dev_get_drvdata(dev);
 	struct tegra_devfreq_device *actmon_dev;
+	unsigned long cur_freq;
 
-	stat->current_frequency = tegra->cur_freq * KHZ;
+	cur_freq = READ_ONCE(tegra->cur_freq);
 
 	/* To be used by the tegra governor */
 	stat->private_data = tegra;
 
 	/* The below are to be used by the other governors */
+	stat->current_frequency = cur_freq * KHZ;
 
 	actmon_dev = &tegra->devices[MCALL];
 
@@ -526,7 +528,7 @@ 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 = ACTMON_SAMPLING_PERIOD * tegra->cur_freq;
+	stat->total_time = ACTMON_SAMPLING_PERIOD * cur_freq;
 
 	stat->busy_time = min(stat->busy_time, stat->total_time);
 
-- 
2.21.0


  parent reply	other threads:[~2019-05-01 23:42 UTC|newest]

Thread overview: 74+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20190501234148epcas5p1cc9a8dafa9ee6d8d046d1292b8270727@epcas5p1.samsung.com>
2019-05-01 23:37 ` [PATCH v4 00/16] NVIDIA Tegra devfreq improvements and Tegra20/30 support Dmitry Osipenko
2019-05-01 23:37   ` Dmitry Osipenko
2019-05-01 23:38   ` [PATCH v4 01/16] PM / devfreq: tegra: Fix kHz to Hz conversion Dmitry Osipenko
2019-05-01 23:38     ` Dmitry Osipenko
2019-06-04 10:54     ` Thierry Reding
2019-05-01 23:38   ` [PATCH v4 02/16] PM / devfreq: tegra: Replace readl-writel with relaxed versions Dmitry Osipenko
2019-05-01 23:38     ` Dmitry Osipenko
2019-06-04 10:55     ` Thierry Reding
2019-05-01 23:38   ` [PATCH v4 03/16] PM / devfreq: tegra: Replace write memory barrier with the read barrier Dmitry Osipenko
2019-05-01 23:38     ` Dmitry Osipenko
2019-06-04 10:56     ` Thierry Reding
2019-05-01 23:38   ` [PATCH v4 04/16] PM / devfreq: tegra: Don't ignore clk errors Dmitry Osipenko
2019-05-01 23:38     ` Dmitry Osipenko
2019-06-04 10:57     ` Thierry Reding
2019-05-01 23:38   ` [PATCH v4 05/16] PM / devfreq: tegra: Don't set EMC clock rate to maximum on probe Dmitry Osipenko
2019-05-01 23:38     ` Dmitry Osipenko
2019-06-04 11:00     ` Thierry Reding
2019-06-04 13:05       ` Dmitry Osipenko
2019-05-01 23:38   ` [PATCH v4 06/16] PM / devfreq: tegra: Drop primary interrupt handler Dmitry Osipenko
2019-05-01 23:38     ` Dmitry Osipenko
2019-06-04 11:02     ` Thierry Reding
2019-05-01 23:38   ` [PATCH v4 07/16] PM / devfreq: tegra: Properly disable interrupts Dmitry Osipenko
2019-05-01 23:38     ` Dmitry Osipenko
2019-06-04 11:07     ` Thierry Reding
2019-06-04 13:40       ` Dmitry Osipenko
2019-06-04 14:06         ` Thierry Reding
2019-06-04 14:59           ` Dmitry Osipenko
2019-06-04 22:55         ` Dmitry Osipenko
2019-06-07 16:58           ` Dmitry Osipenko
2019-05-01 23:38   ` [PATCH v4 08/16] PM / devfreq: tegra: Clean up driver's probe / remove Dmitry Osipenko
2019-05-01 23:38     ` Dmitry Osipenko
2019-06-04 11:09     ` Thierry Reding
2019-05-01 23:38   ` Dmitry Osipenko [this message]
2019-05-01 23:38     ` [PATCH v4 09/16] PM / devfreq: tegra: Avoid inconsistency of current frequency value Dmitry Osipenko
2019-06-04 11:14     ` Thierry Reding
2019-05-01 23:38   ` [PATCH v4 10/16] PM / devfreq: tegra: Mark ACTMON's governor as immutable Dmitry Osipenko
2019-05-01 23:38     ` Dmitry Osipenko
2019-06-04 11:15     ` Thierry Reding
2019-05-01 23:38   ` [PATCH v4 11/16] PM / devfreq: tegra: Move governor registration to driver's probe Dmitry Osipenko
2019-05-01 23:38     ` Dmitry Osipenko
2019-06-04 11:15     ` Thierry Reding
2019-05-01 23:38   ` [PATCH v4 12/16] PM / devfreq: tegra: Reconfigure hardware on governor's restart Dmitry Osipenko
2019-05-01 23:38     ` Dmitry Osipenko
2019-06-04 11:17     ` Thierry Reding
2019-05-01 23:38   ` [PATCH v4 13/16] PM / devfreq: tegra: Support Tegra30 Dmitry Osipenko
2019-05-01 23:38     ` Dmitry Osipenko
2019-06-04 11:18     ` Thierry Reding
2019-05-01 23:38   ` [PATCH v4 14/16] PM / devfreq: tegra: Enable COMPILE_TEST for the driver Dmitry Osipenko
2019-05-01 23:38     ` Dmitry Osipenko
2019-06-04 11:20     ` Thierry Reding
2019-06-04 13:53       ` Dmitry Osipenko
2019-06-04 14:10         ` Thierry Reding
2019-06-04 14:18           ` Thierry Reding
2019-06-04 14:41             ` Dmitry Osipenko
2019-06-04 14:50               ` Thierry Reding
2019-06-04 15:15                 ` Dmitry Osipenko
2019-05-01 23:38   ` [PATCH v4 15/16] PM / devfreq: tegra: Rename tegra-devfreq.c to tegra30-devfreq.c Dmitry Osipenko
2019-05-01 23:38     ` Dmitry Osipenko
2019-06-04 11:23     ` Thierry Reding
2019-06-04 14:35       ` Dmitry Osipenko
2019-05-01 23:38   ` [PATCH v4 16/16] PM / devfreq: Introduce driver for NVIDIA Tegra20 Dmitry Osipenko
2019-05-01 23:38     ` Dmitry Osipenko
2019-06-04 11:25     ` Thierry Reding
2019-06-04 13:57       ` Dmitry Osipenko
2019-05-03  0:31   ` [PATCH v4 00/16] NVIDIA Tegra devfreq improvements and Tegra20/30 support Chanwoo Choi
2019-05-03  0:31     ` Chanwoo Choi
2019-05-03  0:52     ` Dmitry Osipenko
2019-05-03  0:52       ` Dmitry Osipenko
2019-06-03 16:52       ` Dmitry Osipenko
2019-06-04  0:49         ` Chanwoo Choi
2019-06-04 23:09           ` Dmitry Osipenko
2019-06-23 17:17             ` Dmitry Osipenko
2019-06-23 23:50               ` Chanwoo Choi
2019-06-24  0:35                 ` Dmitry Osipenko

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