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From: viresh.kumar@linaro.org (Viresh Kumar)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/1] cpufreq: imx6q: imx6ull: use PLL1 for frequency higher than 528MHz
Date: Wed, 2 Aug 2017 09:19:51 +0530	[thread overview]
Message-ID: <20170802034951.GA31169@vireshk-i7> (raw)
In-Reply-To: <1501230993-15812-1-git-send-email-sebastien.szymanski@armadeus.com>

On 28-07-17, 10:36, S?bastien Szymanski wrote:
> Setting the frequency higher than 528Mhz actually sets the ARM
> clock to 528MHz. That's because PLL2 is used as the root clock when the
> frequency is higher than 396MHz.
> 
> cpupower frequency-set -f 792000
> 
> arm_clk_root on the CCM_CLKO2 signal is 528MHz instead of 792MHz.
> 
> [   61.606383] cpu cpu0: 396 MHz, 1025 mV --> 792 MHz, 1225 mV
> 
> pll2                         1  1  528000000 0 0
>    pll2_bypass               1  1  528000000 0 0
>       pll2_bus               3  3  528000000 0 0
> 	 ca7_secondary_sel   1  1  528000000 0 0
> 	    step             1  1  528000000 0 0
> 	       pll1_sw       1  1  528000000 0 0
> 		  arm        1  1  528000000 0 0
> 
> Fixes this by using the PLL1 as the root clock when the frequency is
> higher than 528MHz.
> 
> cpupower frequency-set -f 792000
> 
> arm_clk_root on the CCM_CLKO2 signal is now 792MHz as expected.
> 
> [   69.717987] cpu cpu0: 198 MHz, 950 mV --> 792 MHz, 1225 mV
> 
> pll1               1 1 792000000 0 0
>    pll1_bypass     1 1 792000000 0 0
>       pll1_sys     1 1 792000000 0 0
> 	 pll1_sw   1 1 792000000 0 0
> 	    arm    1 1 792000000 0 0
> 
> Signed-off-by: S?bastien Szymanski <sebastien.szymanski@armadeus.com>
> ---
>  drivers/cpufreq/imx6q-cpufreq.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)

Looks fine to me:

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

@Shawn: Can you also confirm if this looks fine to you ?

-- 
viresh

  parent reply	other threads:[~2017-08-02  3:49 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-28  8:36 [PATCH 1/1] cpufreq: imx6q: imx6ull: use PLL1 for frequency higher than 528MHz Sébastien Szymanski
2017-08-01 23:25 ` Rafael J. Wysocki
2017-08-02  3:49 ` Viresh Kumar [this message]
2017-08-03  2:03 ` Shawn Guo
2017-08-03  7:32   ` Sébastien Szymanski
2017-08-04 11:17     ` Leonard Crestez

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