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
