rtc: rtc-m48t59: rtc-m48t59.0: IRQ index 0 not found

[Corentin Labbe]

Hello

On my SPARC sunblade 100, I got this:
[   13.613727] rtc-m48t59 rtc-m48t59.0: IRQ index 0 not found
[   13.805777] rtc-m48t59 rtc-m48t59.0: registered as rtc0
[   14.385092] rtc-m48t59 rtc-m48t59.0: setting system clock to 2021-03-01T05:34:33 UTC (1614576873)

The IRQ index 0 message is found after 5.5

Testing rtc via hwclock give:
hwclock: ioctl(3, RTC_UIE_ON, 0) to /dev/rtc0 failed: Input/output error
But this hwclock behavior is present also on earlier kernel (tested 4.9.260, 4.19.179 and 4.14.224).

Does this Input/output error is normal ? (I think no)

Regards