On Sat, Sep 11, 2021 at 8:59 AM Alexandre Belloni
[off-list ref] wrote:

The broken down time conversion is similar to what is done
in the time subsystem since v5.14.

By "similar" you mean "identical", no?

Why is the rtc subsystem not just using the generic time64_to_tm()?

Yes, yes, I realize that due to historical mistakes, there's a
duplicate 'struct rtc_time' struct, but it turns out that that is
_identical_ to 'struct tm' except it also has a 'int tm_isdst' at the
end.

So you could literally make a union of the two, pass the 'struct tm'
part down to the generic code, and just do

     rtc_tm->tm_isdst = 0;

at the end.

Rather than have a duplicate copy of that admittedly clever Neri and
Schneider algorithm.

Hmm?

             Linus