linux-kernel - [PATCH v7 13/19] PM / devfreq: tegra30: Increase sampling period to 16ms

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Message-Id: <20191029220019.26773-14-digetx@gmail.com>
Date:   Wed, 30 Oct 2019 01:00:13 +0300
From:   Dmitry Osipenko <digetx@...il.com>
To:     Thierry Reding <thierry.reding@...il.com>,
        MyungJoo Ham <myungjoo.ham@...sung.com>,
        Kyungmin Park <kyungmin.park@...sung.com>,
        Chanwoo Choi <cw00.choi@...sung.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Tomeu Vizoso <tomeu.vizoso@...labora.com>,
        Peter Geis <pgwipeout@...il.com>
Cc:     linux-pm@...r.kernel.org, linux-tegra@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH v7 13/19] PM / devfreq: tegra30: Increase sampling period to 16ms

Increase sampling period by 4ms to get a nicer pow2 value, converting
diving into shifts in the code. That's more preferable for Tegra30 that
doesn't have hardware divider instructions because of older Cortex-A9 CPU.
In a result boosting events are delayed by 4ms, which is not sensible in
practice at all.

Reviewed-by: Chanwoo Choi <cw00.choi@...sung.com>
Tested-by: Peter Geis <pgwipeout@...il.com>
Signed-off-by: Dmitry Osipenko <digetx@...il.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 9da62f695859..9cbee82880ff 100644
--- a/drivers/devfreq/tegra30-devfreq.c
+++ b/drivers/devfreq/tegra30-devfreq.c
@@ -67,7 +67,7 @@
  * translates to 2 ^ (K_VAL + 1). ex: 2 ^ (6 + 1) = 128
  */
 #define ACTMON_AVERAGE_WINDOW_LOG2			6
-#define ACTMON_SAMPLING_PERIOD				12 /* ms */
+#define ACTMON_SAMPLING_PERIOD				16 /* ms */
 #define ACTMON_DEFAULT_AVG_BAND				6  /* 1/10 of % */
 
 #define KHZ							1000
-- 
2.23.0