linux-kernel - Re: [PATCH 03/12] ARM: normalize clk API for older platforms

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Message-ID: <e5b9e449-62c8-948d-e6c0-fc5a575038b6@ti.com>
Date:   Fri, 21 Jul 2017 15:14:46 +0530
From:   Sekhar Nori <nsekhar@...com>
To:     Arnd Bergmann <arnd@...db.de>
CC:     Kevin Hilman <khilman@...nel.org>,
        Hartley Sweeten <hsweeten@...ionengravers.com>,
        Alexander Sverdlin <alexander.sverdlin@...il.com>,
        Eric Miao <eric.y.miao@...il.com>,
        Haojian Zhuang <haojian.zhuang@...il.com>,
        Wan ZongShun <mcuos.com@...il.com>,
        linux-clk <linux-clk@...r.kernel.org>,
        Stephen Boyd <sboyd@...eaurora.org>,
        Michael Turquette <mturquette@...libre.com>,
        Russell King <linux@...linux.org.uk>,
        Alexandre Bailon <abailon@...libre.com>,
        Masahiro Yamada <yamada.masahiro@...ionext.com>,
        Dmitry Eremin-Solenikov <dbaryshkov@...il.com>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 03/12] ARM: normalize clk API for older platforms

On Friday 21 July 2017 01:47 PM, Arnd Bergmann wrote:
> On Fri, Jul 21, 2017 at 10:05 AM, Sekhar Nori <nsekhar@...com> wrote:
> 
>>> diff --git a/arch/arm/mach-davinci/clock.c b/arch/arm/mach-davinci/clock.c
>>> index f5dce9b4e617..89586779526c 100644
>>> --- a/arch/arm/mach-davinci/clock.c
>>> +++ b/arch/arm/mach-davinci/clock.c
>>> @@ -218,6 +218,12 @@ int clk_set_parent(struct clk *clk, struct clk *parent)
>>>  }
>>>  EXPORT_SYMBOL(clk_set_parent);
>>>
>>> +struct clk *clk_get_parent(struct clk *clk)
>>> +{
>>> +     return clk->parent;
>>> +}
>>> +EXPORT_SYMBOL(clk_get_parent);
>>
>> For mach-davinci change:
>>
>> Acked-by: Sekhar Nori <nsekhar@...com>
> 
> Thanks!
> 
>>> diff --git a/arch/arm/mach-ep93xx/clock.c b/arch/arm/mach-ep93xx/clock.c
>>> index 39ef3b613912..c1c91fc6e178 100644
>>> --- a/arch/arm/mach-ep93xx/clock.c
>>> +++ b/arch/arm/mach-ep93xx/clock.c
>>> @@ -323,6 +323,27 @@ unsigned long clk_get_rate(struct clk *clk)
>>>  }
>>>  EXPORT_SYMBOL(clk_get_rate);
>>>
>>> +long clk_round_rate(struct clk *clk, unsigned long rate)
>>> +{
>>> +     WARN_ON(clk);
>>> +     return 0;
>>> +}
>>> +EXPORT_SYMBOL(clk_round_rate);
>>
>> Its probably better to WARN_ON_ONCE(). Also, since NULL clk is valid, it
>> should be probably be WARN_ON_ONCE(1).
> 
> I thought about trying to make it as correct as possible, but then went for
> the opposite approach and instead just made the functions as small as
> possible to avoid bloat while having the warning in there along with an
> obviously wrong implementation. Apparently the davinci version unlike
> the others ended up being a correct one after all (let me know if you
> want to have a NULL pointer check there).

Yeah, that would be better. Thanks!

Regards,
Sekhar