| Re: [chrony-dev] [PATCH v1] rtc: handle uninitialized RTC |
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- To: "mlichvar@xxxxxxxxxx" <mlichvar@xxxxxxxxxx>
- Subject: Re: [chrony-dev] [PATCH v1] rtc: handle uninitialized RTC
- From: SCHNEIDER Johannes <johannes.schneider@xxxxxxxxxxxxxxxxxxxx>
- Date: Mon, 1 Jul 2024 07:50:09 +0000
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- Thread-topic: [chrony-dev] [PATCH v1] rtc: handle uninitialized RTC
Hoi,
no there wasn't a kernel side discussion;
On a system where chrony is running it holds the rtc device/file-handle, e.g. has exclusive access and manages the RTC -> there are no other applications reading/handling the RTC.
So this patch adds the missing "userspace handling" for this uninitialized RTC corner case.
gruß
Johannes
________________________________________
From: Miroslav Lichvar <mlichvar@xxxxxxxxxx>
Sent: Monday, July 1, 2024 09:44
To: chrony-dev@xxxxxxxxxxxxxxxxxxxx
Subject: Re: [chrony-dev] [PATCH v1] rtc: handle uninitialized RTC
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On Sun, Jun 30, 2024 at 05:04:00PM +0200, Johannes Schneider wrote:
> Add a configuration option for an "initialization year/timestamp"
> chornyd can use to start an uninitialized RTC, so that the RTC driver
> can continue its start up, and chrony could later trim the RTC to an
> accurate date.
>
> Without this 'kick-off', on systems where the RTC would return -EINVAL
> when being queried either for features, or just being read, chronyd
> would be unable to start the RTC driver ("513 RTC driver not running")
> and hence could/would not set it.
>
> An example RTC where this is the case is RX8130 (of the ds1307
> family), which would return -EINVAL *until* the internal oscillator is
> started by writing a valid date to it.
Wouldn't all applications reading RTC need this patch? I think this
should be addressed in the kernel driver instead. Was there a
discussion about that?
--
Miroslav Lichvar
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