On Wed, Apr 29, 2009 at 02:12:29AM -0400, Nick Guenther wrote: > On Wed, Apr 29, 2009 at 1:27 AM, Claudio Jeker <cje...@diehard.n-r-g.com> > wrote: > > On Tue, Apr 28, 2009 at 05:47:20PM -0400, Nick Guenther wrote: > >> Why do only certain wireless cards support host AP mode or IBSS mode? > >> Is the 'modality' hardwired into the wifi hardware? > >> > >> For the archives (since I couldn't find anything on this), the drivers > >> that support being wireless routers (Host AP mode) are: > >> acs(4), ath(4), pgt(4), ral(4), rtw(4), rum(4), ural(4) and wi(4) > >> > >> Drivers that support joining ad-hoc networks: > >> acx(4), an(4), ath(4), atu(4), atw(4), ipw(4), iwi(4), pgt(4), ral(4), > >> ray(4), rtw(4), rum(4), ural(4), urtw(4), wi(4) > >> > >> Drivers that can be ad-hoc "masters" (is this still correct or are > >> ad-hoc masters outdated?): > >> wi(4) > >> > >> (zyd(4) says the chip has the ability to do ad-hoc but "more work is > >> required", and googling > >> (http://mirror.hamakor.org.il/archives/linux-il/11-2005/18095.html) > >> suggests it can be an access point too) > >> > > > > The list is not correct. acx(4) is quite fine in host-ap mode (I guess > > acs(4) is a typo in the first list). > > Being not able to do host-ap mode on wifi cards are either HW limitations > > or documentation limitation. So not much we can do about it. > > > > Oh yeah, I meant acx, oops. These newfangled qwerty keyboards, you know... > > So that's two answers. So is AP mode a hardware-level thing or what? > Or is it that certain firmware/chipsets implement it themselves and > only allow the driver to activate it (or rather, don't, in most > cases). Does the same apply or not apply to ad hoc mode? >
host-ap mode needs to be able to send out some very specific messages that are not needed for normal client operation. If the HW/firmware or whatever does not support us to generate these packets the card will not support host-ap mode. Some drivers support host-ap mode even though the HW is actually not capable of being a real AP because some parts of the spec can not be satisfied (stuff like power saving mode for example). While it works somewhat it fails to be spec conformant. -- :wq Claudio
