From: Alexandre Belloni <alexandre.belloni@bootlin.com>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>,
linux-rtc@vger.kernel.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] rtc: pcf-8563: Report previously detected low-voltage via RTC_VL_BACKUP_LOW
Date: Tue, 11 Jul 2023 22:54:39 +0200 [thread overview]
Message-ID: <2023071120543925735a3a@mail.local> (raw)
In-Reply-To: <69dd51b9-aab1-a9ec-91c2-b1dc79797f10@siemens.com>
On 11/07/2023 09:27:14+0200, Jan Kiszka wrote:
> >>> Nope, that could be easily avoided in software. The actual problem is
> >>> that the VL bit is not settable (clear-on-write). And that means we
> >>> can't do anything about losing the low battery information across
> >>> reboots - but that's no difference to the situation with the existing
> >>> driver.
> >>>
> >>> There is no "fix" for userspace as there is no standard framework to
> >>> read-out the status early and retrieve it from there when the user asks
> >>> for it. That's best done in the kernel.
> >>
> >> That's not true, nothing prevents userspace from reading the battery
> >> status before setting the time and destroying the information which is
> >> exactly what you should be doing.
> >
> > What is your "userspace"? Mine is stock Debian with systemd and
> > timesyncd enabled. But there is no framework to read the status early
> > enough and propagate that after timesyncd did its job. Any concrete
> > suggestion to "fix" userspace?
> >
>
> Ping - I still have seen no suggestion to improve this situation otherwise.
>
You can get systemd or any daemon to read the rtc flag before systemd
decides to use NTP and set the time, destroying the information.
This is a systemd issue, not a kernel issue. I already have to handle
two other issues caused by systemd because they don't want to budge, I
will not take a third one.
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
prev parent reply other threads:[~2023-07-11 20:54 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-09 21:04 [PATCH] rtc: pcf-8563: Report previously detected low-voltage via RTC_VL_BACKUP_LOW Jan Kiszka
2023-06-10 8:31 ` Alexandre Belloni
2023-06-11 13:38 ` Jan Kiszka
2023-06-11 15:11 ` Alexandre Belloni
2023-06-11 16:28 ` Jan Kiszka
2023-06-11 22:16 ` Alexandre Belloni
2023-06-12 6:49 ` Jan Kiszka
2023-07-11 7:27 ` Jan Kiszka
2023-07-11 20:54 ` Alexandre Belloni [this message]
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