linux-kernel - Re: [PATCH v1 1/2] x86/rtc: Add option to skip using RTC

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Message-ID: <a6717e97-01cf-771c-8467-be5946528dd0@linux.intel.com>
Date:   Fri, 23 Aug 2019 11:37:38 +0800
From:   "Tanwar, Rahul" <rahul.tanwar@...ux.intel.com>
To:     Andy Shevchenko <andriy.shevchenko@...el.com>
Cc:     tglx@...utronix.de, mingo@...hat.com, bp@...en8.de, hpa@...or.com,
        tony.luck@...el.com, x86@...nel.org, a.zummo@...ertech.it,
        alexandre.belloni@...tlin.com, robh+dt@...nel.org,
        mark.rutland@....com, linux-rtc@...r.kernel.org,
        devicetree@...r.kernel.org, alan@...ux.intel.com,
        linux-kernel@...r.kernel.org, qi-ming.wu@...el.com,
        cheol.yong.kim@...el.com, rahul.tanwar@...el.com
Subject: Re: [PATCH v1 1/2] x86/rtc: Add option to skip using RTC

Hi Andy,

On 22/8/2019 9:04 PM, Andy Shevchenko wrote:
> On Thu, Aug 22, 2019 at 05:26:33PM +0800, Tanwar, Rahul wrote:
>> On 22/8/2019 5:02 PM, Andy Shevchenko wrote:
>>> On Thu, Aug 22, 2019 at 03:44:03PM +0800, Rahul Tanwar wrote:
>>>> Use a newly introduced optional "status" property of "motorola,mc146818"
>>>> compatible DT node to determine if RTC is supported. Skip read/write from
>>>> RTC device only when this node is present and status is "disabled". In all
>>>> other cases, proceed as before.
>>> Can't we rather update ->get_wallclock() and ->set_wallclock() based on this?
>>
>> get_wallclock() and set_wallclock() are function pointers of platform_ops
>>
>> which are initialized to mach_get_cmos_time() and mach_set_rtc_mmss()
>>
>> at init time. Since adding a new platform to override these functions is
>>
>> discouraged, so the only way is to modify RTC get/set functions.
> Shouldn't it be platform agnostic code?
> So, my point is, instead of hacking two functions, perhaps better to avoid them
> at all.

Sorry, i could not understand your point. The changes are platform

agnostic i.e. it doesn't break existing use cases. Are you recommending

to add a new platform and make changes there ?

Regards,

Rahul

>
>