Re: [PATCH v4 7/8] ARM: dts: Exynos5422: fix OPP tables

From	Krzysztof Kozlowski <k.kozlowski@samsung.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v4 7/8] ARM: dts: Exynos5422: fix OPP tables
Date	2015-12-09 01:40 +0100
Message-ID	<qDAXv-10W-3@gated-at.bofh.it> (permalink)
References	<qD8yd-85F-3@gated-at.bofh.it> <qD8HV-8aH-31@gated-at.bofh.it> <qDlF8-8d1-7@gated-at.bofh.it> <qDqOu-30G-13@gated-at.bofh.it>
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On 08.12.2015 22:41, Javier Martinez Canillas wrote:
> Hello Krzysztof,
> 
> On 12/08/2015 05:13 AM, Krzysztof Kozlowski wrote:
>> On 08.12.2015 03:18, Bartlomiej Zolnierkiewicz wrote:
>>> From: Ben Gamari <ben@smart-cactus.org>
>>>
>>> The Exynos 5422 is identical to the 5800 except for the fact that it
>>> boots from the A7 cores. Consequently, the core numbering is different:
>>> cores 0-3 are A7s whereas 4-7 are A15s.
>>>
>>> We can reuse the device tree of the 5800 for the 5422 but we must take
>>> care to override the OPP tables and CPU clocks.  These are otherwise
>>> inherited from the exynos5800 devicetree, which has the CPU clusters
>>> reversed compared to the 5422. This results in the A15 cores only
>>> reaching 1.4GHz, the maximum rate of the KFC clock.
>>>
>>> Cc: Javier Martinez Canillas <javier@osg.samsung.com>
>>> Signed-off-by: Ben Gamari <ben@smart-cactus.org>
>>> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
>>> ---
>>>  arch/arm/boot/dts/exynos5422-cpus.dtsi | 10 ++++++++++
>>>  1 file changed, 10 insertions(+)
>>>
>>
>> This looks like a very-non-atomic way of handling a change. You added
>> opp tables to exynos5420 before so at that time they will be applied to
>> Odroid XU3 family which uses different CPU order. After that you are
>> fixing the tables to proper CPU order. Direct bisectability probably
>> won't be an issue because all of DTS would go to separate branch... but
>> the logic behind confuses.
>>
> 
> Agreed.
> 
>> I think this should be squashed into 3/8.
>>
> 
> I think the patch should be split in two changes, the CPUs device nodes
> having the wrong clock for clusters is a bug and has to be fixed in a
> patch before adding the OPP tables and the OPP tables changes should be
> separated and merged with patch 3/8 as you suggest.

I don't get the point about wrong clock (bug). Where is the bug? Beside
of course what was introduced in 3/8 and it is not valid for reversed
cluster order.

Best regards,
Krzysztof

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Thread

[PATCH v4 0/8] cpufreq: add generic cpufreq driver support for  Exynos542x/5800 platforms Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2015-12-07 19:20 +0100
  [PATCH v4 1/8] ARM: dts: Exynos542x/5800: add cluster regulator supply  properties Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2015-12-07 19:20 +0100
    Re: [PATCH v4 1/8] ARM: dts: Exynos542x/5800: add cluster regulator  supply properties Krzysztof Kozlowski <k.kozlowski@samsung.com> - 2015-12-08 07:50 +0100
    Re: [PATCH v4 1/8] ARM: dts: Exynos542x/5800: add cluster regulator  supply properties Markus Reichl <m.reichl@fivetechno.de> - 2015-12-08 11:20 +0100
  [PATCH v4 2/8] clk: samsung: exynos5420: add cpu clock configuration  data and instantiate cpu clock Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2015-12-07 19:20 +0100
  [PATCH v4 3/8] ARM: dts: Exynos5420: add CPU OPP properties Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2015-12-07 19:30 +0100
    Re: [PATCH v4 3/8] ARM: dts: Exynos5420: add CPU OPP properties Viresh Kumar <viresh.kumar@linaro.org> - 2015-12-08 07:30 +0100
    Re: [PATCH v4 3/8] ARM: dts: Exynos5420: add CPU OPP properties Krzysztof Kozlowski <k.kozlowski@samsung.com> - 2015-12-08 08:20 +0100
  [PATCH v4 8/8] ARM: Exynos: use generic cpufreq driver for  Exynos5422/5800 Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2015-12-07 19:30 +0100
  [PATCH v4 6/8] ARM: dts: Exynos5800: fix CPU OPP Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2015-12-07 19:30 +0100
    Re: [PATCH v4 6/8] ARM: dts: Exynos5800: fix CPU OPP Krzysztof Kozlowski <k.kozlowski@samsung.com> - 2015-12-08 09:10 +0100
  [PATCH v4 7/8] ARM: dts: Exynos5422: fix OPP tables Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2015-12-07 19:30 +0100
    Re: [PATCH v4 7/8] ARM: dts: Exynos5422: fix OPP tables Krzysztof Kozlowski <k.kozlowski@samsung.com> - 2015-12-08 09:20 +0100
      Re: [PATCH v4 7/8] ARM: dts: Exynos5422: fix OPP tables Javier Martinez Canillas <javier@osg.samsung.com> - 2015-12-08 14:50 +0100
        Re: [PATCH v4 7/8] ARM: dts: Exynos5422: fix OPP tables Krzysztof Kozlowski <k.kozlowski@samsung.com> - 2015-12-09 01:40 +0100
          Re: [PATCH v4 7/8] ARM: dts: Exynos5422: fix OPP tables Javier Martinez Canillas <javier@osg.samsung.com> - 2015-12-09 03:20 +0100
      Re: [PATCH v4 7/8] ARM: dts: Exynos5422: fix OPP tables Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2015-12-10 17:00 +0100
  [PATCH v4 4/8] ARM: Exynos: use generic cpufreq driver for Exynos5420 Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2015-12-07 19:30 +0100
    Re: [PATCH v4 4/8] ARM: Exynos: use generic cpufreq driver for  Exynos5420 Krzysztof Kozlowski <k.kozlowski@samsung.com> - 2015-12-08 08:40 +0100
      Re: [PATCH v4 4/8] ARM: Exynos: use generic cpufreq driver for  Exynos5420 Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2015-12-10 15:20 +0100
        Re: [PATCH v4 4/8] ARM: Exynos: use generic cpufreq driver for  Exynos5420 Krzysztof Kozlowski <k.kozlowski@samsung.com> - 2015-12-11 02:20 +0100
  [PATCH v4 5/8] clk: samsung: exynos5422/5800: fix cpu clock  configuration data Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> - 2015-12-07 19:30 +0100
  Re: [PATCH v4 0/8] cpufreq: add generic cpufreq driver support for  Exynos542x/5800 platforms Viresh Kumar <viresh.kumar@linaro.org> - 2015-12-08 07:20 +0100
    Re: [PATCH v4 0/8] cpufreq: add generic cpufreq driver support for  Exynos542x/5800 platforms Viresh Kumar <viresh.kumar@linaro.org> - 2015-12-08 07:30 +0100
  Re: [PATCH v4 0/8] cpufreq: add generic cpufreq driver support for  Exynos542x/5800 platforms Javier Martinez Canillas <javier@osg.samsung.com> - 2015-12-09 14:20 +0100

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