From: k.kozlowski@samsung•com (Krzysztof Kozlowski)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v4 7/8] ARM: dts: Exynos5422: fix OPP tables
Date: Wed, 09 Dec 2015 09:34:09 +0900 [thread overview]
Message-ID: <56677701.10809@samsung.com> (raw)
In-Reply-To: <5666DE25.7090708@osg.samsung.com>
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
next prev parent reply other threads:[~2015-12-09 0:34 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-07 18:18 [PATCH v4 0/8] cpufreq: add generic cpufreq driver support for Exynos542x/5800 platforms Bartlomiej Zolnierkiewicz
2015-12-07 18:18 ` [PATCH v4 1/8] ARM: dts: Exynos542x/5800: add cluster regulator supply properties Bartlomiej Zolnierkiewicz
2015-12-08 6:48 ` Krzysztof Kozlowski
2015-12-08 10:16 ` Markus Reichl
2015-12-07 18:18 ` [PATCH v4 2/8] clk: samsung: exynos5420: add cpu clock configuration data and instantiate cpu clock Bartlomiej Zolnierkiewicz
2015-12-07 18:18 ` [PATCH v4 3/8] ARM: dts: Exynos5420: add CPU OPP properties Bartlomiej Zolnierkiewicz
2015-12-08 6:28 ` Viresh Kumar
2015-12-08 7:17 ` Krzysztof Kozlowski
2015-12-07 18:18 ` [PATCH v4 4/8] ARM: Exynos: use generic cpufreq driver for Exynos5420 Bartlomiej Zolnierkiewicz
2015-12-08 7:36 ` Krzysztof Kozlowski
2015-12-10 14:18 ` Bartlomiej Zolnierkiewicz
2015-12-11 1:13 ` Krzysztof Kozlowski
2015-12-07 18:18 ` [PATCH v4 5/8] clk: samsung: exynos5422/5800: fix cpu clock configuration data Bartlomiej Zolnierkiewicz
2015-12-07 18:18 ` [PATCH v4 6/8] ARM: dts: Exynos5800: fix CPU OPP Bartlomiej Zolnierkiewicz
2015-12-08 8:07 ` Krzysztof Kozlowski
2015-12-07 18:18 ` [PATCH v4 7/8] ARM: dts: Exynos5422: fix OPP tables Bartlomiej Zolnierkiewicz
2015-12-08 8:13 ` Krzysztof Kozlowski
2015-12-08 13:41 ` Javier Martinez Canillas
2015-12-09 0:34 ` Krzysztof Kozlowski [this message]
2015-12-09 2:19 ` Javier Martinez Canillas
2015-12-10 15:57 ` Bartlomiej Zolnierkiewicz
2015-12-07 18:18 ` [PATCH v4 8/8] ARM: Exynos: use generic cpufreq driver for Exynos5422/5800 Bartlomiej Zolnierkiewicz
2015-12-08 6:17 ` [PATCH v4 0/8] cpufreq: add generic cpufreq driver support for Exynos542x/5800 platforms Viresh Kumar
2015-12-08 6:29 ` Viresh Kumar
2015-12-09 13:13 ` Javier Martinez Canillas
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