On Tue, Dec 4, 2012 at 11:14 AM, Johannes Berg <johannes at sipsolutions.net> 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. > > Signed-off-by: Johannes Berg <johannes.berg at intel.com> Acked-by: Luis R. Rodriguez <mcgrof at do-not-panic.com> I'd add into the commit log: The current issue was spotted when dealing with the world regulatory domain which had overlapping frequency rules -- that is you had to evaluate two ranges to determine if you can use HT40 channel. The primary HT40 channel would fit into one freq range and the subchannel would fit into another frequency band. An additional change is possible however and that is to have the kernel check not for 40 MHz requirement on subchannels but only 20 MHz but this alone could lead to secondary issues by the current implicit architecture support of overlapping frequencies which are we currently evaluating. Luis
