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Message-ID: <51780976.8020608@linaro.org>
Date: Wed, 24 Apr 2013 09:33:58 -0700
From: John Stultz <john.stultz@linaro.org>
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To: Kay Sievers <kay@vrfy.org>
CC: LKML <linux-kernel@vger.kernel.org>
Subject: Re: CONFIG_RTC_HCTOSYS lost on x86 with ALWAYS_USE_PERSISTENT_CLOCK
 changes?
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On 04/23/2013 08:51 PM, Kay Sievers wrote:
> On Wed, Apr 24, 2013 at 5:33 AM, Kay Sievers <kay@vrfy.org> wrote:
>
>> Also:
>>    $ cat /sys/class/rtc/rtc0/hctosys
>>    0
>> always carried "1", and this now breaks setups which expect an
>> automatically created symlink /dev/rtc to the actual "system rtc".
> We used to do this in upstream standard udev rules:
>    SUBSYSTEM=="rtc", ATTR{hctosys}=="1", MODE="0644"
>    http://cgit.freedesktop.org/systemd/systemd/tree/rules/50-udev-default.rules#n18
>
> If that information is expected to be gone now, we need to update some
> tools. Whats' the proper way now to find the "system rtc" to use?

No we'll revert. Can't break userland.

But as to your question, if there's only one rtc, I'd consider it the 
"system rtc", only adjusting the link if a second RTC appears and has 
the hctosys flag set.

thanks
-john