Re: [PATCH V2] regdb: Generalize the mW to dBm power conversion

[Johannes Berg <johannes@sipsolutions.net>]

On Tue, 2014-05-27 at 21:41 +0530, Krishna Chaitanya wrote:
> On Tue, May 27, 2014 at 9:27 PM, Johannes Berg
> <johannes@sipsolutions.net> wrote:
> >
> > On Mon, 2014-05-26 at 18:01 +0530, chaitanya.mgit@gmail.com wrote:
> > > Generalize the power conversion from mW to dBm
> > > using log. This should fix the below compilation
> > > error for country NO which adds a new power value
> > > 2000mW which is not handled earlier.
> > >
> > >  CC [M]  net/wireless/wext-sme.o
> > >  CC [M]  net/wireless/regdb.o
> > > net/wireless/regdb.c:1130:1: error: Unknown undeclared here (not in
> > > a function)
> > > net/wireless/regdb.c:1130:9: error: expected } before power
> > > make[2]: *** [net/wireless/regdb.o] Error 1
> > > make[1]: *** [net/wireless] Error 2
> > > make: *** [net] Error 2
> > >
> > > Reported-By:  John Walker <john@x109.net>
> > > Signed-off-by: Chaitanya T K <chaitanya.mgit@gmail.com>
> > >
> > > ---
> > >  net/wireless/genregdb.awk |   12 +-----------
> > >  1 file changed, 1 insertion(+), 11 deletions(-)
> > >
> > > diff --git a/net/wireless/genregdb.awk b/net/wireless/genregdb.awk
> > > index 4119833..949ee38 100644
> > > --- a/net/wireless/genregdb.awk
> > > +++ b/net/wireless/genregdb.awk
> > > @@ -68,17 +68,7 @@ function parse_reg_rule()
> > >       sub(/,/, "", units)
> > >       dfs_cac = $9
> > >       if (units == "mW") {
> > > -             if (power == 100) {
> > > -                     power = 20
> > > -             } else if (power == 200) {
> > > -                     power = 23
> > > -             } else if (power == 500) {
> > > -                     power = 27
> > > -             } else if (power == 1000) {
> > > -                     power = 30
> > > -             } else {
> > > -                     print "Unknown power value in database!"
> > > -             }
> > > +             power = 10 * (log(power)/log(10))
> >
> > This patch is wrong :-)
> > Bonus points for those who can figure it out without looking at the one
> > I'm committing ;-)
> >
> Forgot to handle the print to the file. (Looked at the commit :-))

No, the print worked - the difference is that %.0f rounds, and %d
truncates (so that for power=500 it comes out wrong for %d)

johannes