linux-kernel - Re: [PATCH 1/3] ARM: dts: Add PMU reg node to exynos4210

Open Source and information security mailing list archives

Message-ID: <CAGm_ybi+QiC95-aJtzbpY8CCv9f6+NDC4HHrC8RuCmkUHDGB5A@mail.gmail.com>
Date:	Thu, 24 Apr 2014 18:56:47 +0530
From:	Vikas Sajjan <sajjan.linux@...il.com>
To:	Pankaj Dubey <pankaj.dubey@...sung.com>
Cc:	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	linux-kernel@...r.kernel.org,
	linux-samsung-soc <linux-samsung-soc@...r.kernel.org>,
	devicetree@...r.kernel.org, mark.rutland@....com,
	Kukjin Kim <kgene.kim@...sung.com>, linux@....linux.org.uk,
	pawel.moll@....com, ijc+devicetree@...lion.org.uk,
	Rob Herring <robh+dt@...nel.org>, galak@...eaurora.org,
	chow.kim@...sung.com, Tomasz Figa <t.figa@...sung.com>,
	Tomasz Figa <tomasz.figa@...il.com>,
	sunil joshi <joshi@...sung.com>
Subject: Re: [PATCH 1/3] ARM: dts: Add PMU reg node to exynos4210

Hi Pankaj,

On Thu, Apr 24, 2014 at 6:27 PM, Pankaj Dubey <pankaj.dubey@...sung.com> wrote:
> Hi Vikas,
>
>
> On 04/24/2014 08:59 PM, Vikas Sajjan wrote:
>>
>> +Tomasz
>>
>>
>> On Wed, Apr 2, 2014 at 1:32 PM, Pankaj Dubey <pankaj.dubey@...sung.com>
>> wrote:
>>>
>>> This patch adds pmu regnode to exynos4210 dtsi to handle
>>> PMU register access via DT.
>>>
>>> Signed-off-by: Pankaj Dubey <pankaj.dubey@...sung.com>
>>> ---
>>>   arch/arm/boot/dts/exynos4210.dtsi |    5 +++++
>>>   1 file changed, 5 insertions(+)
>>>
>>> diff --git a/arch/arm/boot/dts/exynos4210.dtsi
>>> b/arch/arm/boot/dts/exynos4210.dtsi
>>> index cacf614..0a2c0fe 100644
>>> --- a/arch/arm/boot/dts/exynos4210.dtsi
>>> +++ b/arch/arm/boot/dts/exynos4210.dtsi
>>> @@ -81,6 +81,11 @@
>>>                  interrupts = <2 2>, <3 2>;
>>>          };
>>>
>>> +       pmu_system_controller: system-controller@...20000 {
>>> +               compatible = "samsung,exynos4210-pmu", "syscon";
>>> +               reg = <0x10020000 0x5000>;
>>
>> Can we have 2 strings as "compatible" and these 2 strings are used by
>> 2 different driver?
>>
>> Because once syscon driver gets probed, exynos-pmu.c [1] driver will
>> never be probed.
>>
>> The new PMU driver [1] completely relies on this. With just
>> exynos_defconfig, you will not notice this issue, since syscon is NOT
>> enabled by exynos_defconfig. When I enabled "System Controller
>> Register R/W Based on Regmap" in menuconfig, I could see PMU driver
>> [1] is NEVER probed.
>>
>> Let me know, if I am missing something.
>>
>>   [1] http://www.spinics.net/lists/arm-kernel/msg319750.html
>
>
> You are correct. We also missed this because "SYSCON" option was
> not enabled in exynos_defconfig.
> I noticed this during preparation of V2 when I planned to use
> "early_syscon_init" [1] as suggested by Sylwester here [2].
>
OK.

> In V2 I will take care of this. I hope soon I will be able to post second

So in your V2, will you be adding new DT node altogether for PMU?
Because with existing DT node "pmu_system_controller"  (which is
already present in mailine for exynos 5250) and SYSCON driver enable,
exynos PMU driver will NEVER probed.

> version of this series, just waiting for testing and internal code review.
>
> [1] https://lkml.org/lkml/2014/4/8/239
> [2] https://lkml.org/lkml/2014/4/2/171
>
>>
>>
>>> +       };
>>> +
>>>          pinctrl_0: pinctrl@...00000 {
>>>                  compatible = "samsung,exynos4210-pinctrl";
>>>                  reg = <0x11400000 0x1000>;
>>> --
>>> 1.7.10.4
>>>
>>>
>>> _______________________________________________
>>> linux-arm-kernel mailing list
>>> linux-arm-kernel@...ts.infradead.org
>>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
>
>
> --
> Best Regards,
> Pankaj Dubey
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives