linux-kernel - Re: [PATCH V4] ARM: mach-shmobile: Don't init CNTVOFF/counter if PSCI is available

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Message-ID: <c45a056f-80d5-187d-e865-fb66d514830a@gmail.com>
Date:   Tue, 14 May 2019 19:51:30 +0300
From:   Oleksandr <olekstysh@...il.com>
To:     Julien Grall <julien.grall@....com>,
        linux-renesas-soc@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     horms@...ge.net.au, magnus.damm@...il.com, linux@...linux.org.uk,
        geert@...ux-m68k.org,
        Oleksandr Tyshchenko <oleksandr_tyshchenko@...m.com>
Subject: Re: [PATCH V4] ARM: mach-shmobile: Don't init CNTVOFF/counter if PSCI
 is available


On 14.05.19 19:13, Julien Grall wrote:
> Hi,

Hi Julien


>
> On 14/05/2019 17:06, Oleksandr Tyshchenko wrote:
>> diff --git a/arch/arm/mach-shmobile/setup-rcar-gen2.c 
>> b/arch/arm/mach-shmobile/setup-rcar-gen2.c
>> index eea60b2..64e3abd 100644
>> --- a/arch/arm/mach-shmobile/setup-rcar-gen2.c
>> +++ b/arch/arm/mach-shmobile/setup-rcar-gen2.c
>> @@ -17,6 +17,7 @@
>>   #include <linux/of.h>
>>   #include <linux/of_fdt.h>
>>   #include <linux/of_platform.h>
>> +#include <linux/psci.h>
>>   #include <asm/mach/arch.h>
>>   #include <asm/secure_cntvoff.h>
>>   #include "common.h"
>> @@ -63,6 +64,15 @@ void __init rcar_gen2_timer_init(void)
>>       void __iomem *base;
>>       u32 freq;
>>   +    /*
>> +     * If PSCI is available then most likely we are running on 
>> PSCI-enabled
>> +     * U-Boot which, we assume, has already taken care of resetting 
>> CNTVOFF
>> +     * and updating counter module before switching to non-secure mode
>> +     * and we don't need to.
>> +     */
>> +    if (psci_ops.cpu_on) > +        goto skip_update;
> Are you sure this is working when ARM_PSCI_FW is not selected? Is it 
> possible to have a .config for RCAR without ARM_PSCI_FW?

Oh, my fault. Mainline shmobile_defconfig has PSCI stuff disabled.

I should have checked for the PSCI operation to be available only if 
CONFIG_ARM_PSCI_FW is defined.

Thank you for pointing this out.


>
> Cheers,
>
-- 
Regards,

Oleksandr Tyshchenko