Message-ID: <1401208951.8146.9.camel@jlt4.sipsolutions.net> (sfid-20140527_184250_224862_6B8D816A)
Subject: Re: [PATCH V2] regdb: Generalize the mW to dBm power conversion
From: Johannes Berg <johannes@sipsolutions.net>
To: Krishna Chaitanya <chaitanya.mgit@gmail.com>
Cc: John Linville <linville@tuxdriver.com>,
	Luis Rodriguez <mcgrof@gmail.com>,
	linux-wireless <linux-wireless@vger.kernel.org>
Date: Tue, 27 May 2014 18:42:31 +0200
In-Reply-To: <CABPxzYK+fhSdEwka9cU3O+VEsJpABViCg9OgdEJ=3t27OLyYTw@mail.gmail.com> (sfid-20140527_181202_456334_621A5E5C)
References: <1401107504-11385-1-git-send-email-chaitanya.mgit@gmail.com>
	 <1401206274.8146.8.camel@jlt4.sipsolutions.net>
	 <CABPxzYK+fhSdEwka9cU3O+VEsJpABViCg9OgdEJ=3t27OLyYTw@mail.gmail.com>
	 (sfid-20140527_181202_456334_621A5E5C)
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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