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Groups > linux.kernel > #1702619 > unrolled thread
| Started by | Shawn Guo <shawnguo@kernel.org> |
|---|---|
| First post | 2017-08-03 04:10 +0200 |
| Last post | 2017-08-03 10:50 +0200 |
| Articles | 2 — 2 participants |
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Re: [PATCH 1/1] cpufreq: imx6q: imx6ull: use PLL1 for frequency higher than 528MHz Shawn Guo <shawnguo@kernel.org> - 2017-08-03 04:10 +0200
Re: [PATCH 1/1] cpufreq: imx6q: imx6ull: use PLL1 for frequency higher than 528MHz Sébastien Szymanski <sebastien.szymanski@armadeus.com> - 2017-08-03 10:50 +0200
| From | Shawn Guo <shawnguo@kernel.org> |
|---|---|
| Date | 2017-08-03 04:10 +0200 |
| Subject | Re: [PATCH 1/1] cpufreq: imx6q: imx6ull: use PLL1 for frequency higher than 528MHz |
| Message-ID | <uadKk-1CS-3@gated-at.bofh.it> |
On Fri, Jul 28, 2017 at 10:36:33AM +0200, Sébastien 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: Sébastien Szymanski <sebastien.szymanski@armadeus.com>
Can you please specify on which SoCs you are seeing this problem? And I
would like invite Anson and Leonard to review it.
Shawn
> ---
> drivers/cpufreq/imx6q-cpufreq.c | 11 +++++++++--
> 1 file changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
> index b6edd3c..e5fba50 100644
> --- a/drivers/cpufreq/imx6q-cpufreq.c
> +++ b/drivers/cpufreq/imx6q-cpufreq.c
> @@ -18,6 +18,7 @@
>
> #define PU_SOC_VOLTAGE_NORMAL 1250000
> #define PU_SOC_VOLTAGE_HIGH 1275000
> +#define FREQ_528_MHZ 528000000
> #define FREQ_1P2_GHZ 1200000000
>
> static struct regulator *arm_reg;
> @@ -110,14 +111,20 @@ static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
> * voltage of 528MHz, so lower the CPU frequency to one
> * half before changing CPU frequency.
> */
> - clk_set_rate(arm_clk, (old_freq >> 1) * 1000);
> - clk_set_parent(pll1_sw_clk, pll1_sys_clk);
> + if ((old_freq * 1000) <= FREQ_528_MHZ) {
> + clk_set_rate(arm_clk, (old_freq >> 1) * 1000);
> + clk_set_parent(pll1_sw_clk, pll1_sys_clk);
> + }
> if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk))
> clk_set_parent(secondary_sel_clk, pll2_bus_clk);
> else
> clk_set_parent(secondary_sel_clk, pll2_pfd2_396m_clk);
> clk_set_parent(step_clk, secondary_sel_clk);
> clk_set_parent(pll1_sw_clk, step_clk);
> + if (freq_hz > FREQ_528_MHZ) {
> + clk_set_rate(pll1_sys_clk, freq_hz);
> + clk_set_parent(pll1_sw_clk, pll1_sys_clk);
> + }
> } else {
> clk_set_parent(step_clk, pll2_pfd2_396m_clk);
> clk_set_parent(pll1_sw_clk, step_clk);
> --
> 2.7.3
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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| From | Sébastien Szymanski <sebastien.szymanski@armadeus.com> |
|---|---|
| Date | 2017-08-03 10:50 +0200 |
| Message-ID | <uajZo-5W2-11@gated-at.bofh.it> |
| In reply to | #1702619 |
Hello,
On 08/03/2017 04:03 AM, Shawn Guo wrote:
> On Fri, Jul 28, 2017 at 10:36:33AM +0200, Sébastien 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: Sébastien Szymanski <sebastien.szymanski@armadeus.com>
>
> Can you please specify on which SoCs you are seeing this problem? And I
> would like invite Anson and Leonard to review it.
My SoC is MCIMX6Y2CVM08AA which is a 792MHz i.MX6ULL. I forgot to
mention that I added the following operating points in my device tree:
operating-points: 792000 1225000
fsl,soc-operating-points: 792000 1175000
Best regards,
>
> Shawn
>
>> ---
>> drivers/cpufreq/imx6q-cpufreq.c | 11 +++++++++--
>> 1 file changed, 9 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
>> index b6edd3c..e5fba50 100644
>> --- a/drivers/cpufreq/imx6q-cpufreq.c
>> +++ b/drivers/cpufreq/imx6q-cpufreq.c
>> @@ -18,6 +18,7 @@
>>
>> #define PU_SOC_VOLTAGE_NORMAL 1250000
>> #define PU_SOC_VOLTAGE_HIGH 1275000
>> +#define FREQ_528_MHZ 528000000
>> #define FREQ_1P2_GHZ 1200000000
>>
>> static struct regulator *arm_reg;
>> @@ -110,14 +111,20 @@ static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
>> * voltage of 528MHz, so lower the CPU frequency to one
>> * half before changing CPU frequency.
>> */
>> - clk_set_rate(arm_clk, (old_freq >> 1) * 1000);
>> - clk_set_parent(pll1_sw_clk, pll1_sys_clk);
>> + if ((old_freq * 1000) <= FREQ_528_MHZ) {
>> + clk_set_rate(arm_clk, (old_freq >> 1) * 1000);
>> + clk_set_parent(pll1_sw_clk, pll1_sys_clk);
>> + }
>> if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk))
>> clk_set_parent(secondary_sel_clk, pll2_bus_clk);
>> else
>> clk_set_parent(secondary_sel_clk, pll2_pfd2_396m_clk);
>> clk_set_parent(step_clk, secondary_sel_clk);
>> clk_set_parent(pll1_sw_clk, step_clk);
>> + if (freq_hz > FREQ_528_MHZ) {
>> + clk_set_rate(pll1_sys_clk, freq_hz);
>> + clk_set_parent(pll1_sw_clk, pll1_sys_clk);
>> + }
>> } else {
>> clk_set_parent(step_clk, pll2_pfd2_396m_clk);
>> clk_set_parent(pll1_sw_clk, step_clk);
>> --
>> 2.7.3
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
--
Sébastien Szymanski
Software engineer, Armadeus Systems
Tel: +33 (0)9 72 29 41 44
Fax: +33 (0)9 72 28 79 26
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