[wireless-regdb] [PATCH] dbparse: remove usable bandwidth check

[Johannes Berg]

On Tue, 2012-12-04 at 21:03 +0100, Johannes Berg wrote:
> On Tue, 2012-12-04 at 21:02 +0100, Johannes Berg wrote:
> > On Tue, 2012-12-04 at 20:14 +0100, Johannes Berg wrote:
> > > From: Johannes Berg <johannes.berg at intel.com>
> > > 
> > > The kernel uses the bandwidth this way: any frequency
> > > rule that is required for any of the 20 MHz subchannels
> > > of a given channel must allow the total bandwidth.
> > > Therefore, this check is wrong -- a frequency rule may
> > > need to be specified with higher bandwidth than it has
> > > to allow to form e.g. HT40 out of subchannels.
> > 
> > This patch, and the other patch, are because we currently interpret the
> > rules this way:
> > 
> > http://johannes.sipsolutions.net/files/chans-old.pdf
> 
> Let me attach that for the archives ...

And give an example :-)

HT40+ on channel 9 uses the range covered by channels 9 and 13. Channel
13 falls into the second freqband, so that must have @40 because in the
kernel we currently check that any freqband that is required for channel
9 or 13 (in this example) allows enough bandwidth for the whole channel.

johannes