[PATCH v1] RFC: rtc: rv8803: avoid bootloop on low voltage of button cell

Michael Walle michael at walle.cc
Wed Feb 8 12:33:48 CET 2023

Am 2023-02-08 12:29, schrieb Oliver Graute:
>> Am 08.02.2023 um 09:32 schrieb Michael Walle <michael at walle.cc>:
>> Am 2023-02-08 08:38, schrieb Oliver Graute:
>>> if the rtc button cell is on low voltage this can result in a 
>>> permanent
>>> bootloop in u-boot because V2F Register is permanent set.
>>> ### Warning: temperature compensation has stopped
>>> ### Warning: Voltage low, data is invalid
>>> resetting ...
>>> With this patch the bootloop is prevented
>>> Signed-off-by: Oliver Graute <oliver.graute at kococonnector.com>
>> I'm curious, how is the call tree here? I don't see the dm_rtc_get()
>> being called during boot. Basically, you are now just ignoring the 
>> error.
> I use dm_rtc_get() in a modified boot/bootm.c to check for a End-Off 
> Live
> booting date. Just to prevent that testers uses devices with out-dated 
> images.
> So if this only affects me so this patch can be ignored.

In this case you should just ignore the return value (and live with
bogus values). Or.. handle it gracefully.


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