[PATCH v2] wireless-regdb: Update regulatory info for Vietnam (VN) for 2025

[Johannes Berg]

On Fri, 2025-05-16 at 16:02 +0700, Duy Hoang wrote:
> 
> * 5470 - 5725 MHz
>   - 500 mW (27 dBm)

So as we found in the ETSI thread, this (500 mW == 27 dBm) isn't
actually what happens, but rather you get 26 dBm.

However, the Vietnam regulations, although seemingly the same as ETSI,
explicitly state 500 mW rather than the 3 dB reduction from 1 W that's
stated in Germany!

I'd still probably argue that the difference between 500 and 501.187 is
small enough that you can state 27 dB here in the db, rather than
stating 500mW.

I'm not sure we should make the processing scripts do rounding in this
case, perhaps we should, if we decide that we want to ignore the
difference of 0.237%?

johannes