[PATCH v2] hostap: Support ht-cap over-rides.

Jouni Malinen j at w1.fi
Sat Nov 19 11:42:13 EST 2011


On Sat, Nov 19, 2011 at 08:03:48AM -0800, Ben Greear wrote:
> Sure, but the rate algorithms may not optimize perfectly for every
> user.  If packet loss is very painful (maybe for VOIP?), then
> it may be worth running at a lower rate for less packet loss?

Sure, but that should not really have anything to do with
wpa_supplicant.

> Why did we allow setting rates in the a/b/g modes (even if not
> through hostap) ?

As you point out, that is not in wpa_supplicant.. And neither should
these HT capability overrides.

> Would it help if I made it something that is only compiled in when
> the user selects the option in the config file?

Some, but it does leave the extra maintenance effort and makes code
uglier.

Unfortunately, it looks like the HT disabling capability in nl80211 was
added in a way that in practice requires changes in wpa_supplicant. It
would have been much easier from my view point if this could have been
done with iw without having to make wpa_supplicant aware of all the HT
details. It looks like your patch for wpa_supplicant does not actually
match with this design since it uses global configuration parameters
instead of per-network configuration. It is difficult to see why anyone
would want to use that type of configuration.

I could see some reasonable use cases for being able to disable HT in a
network (though, more likely as a per-network rather than global
parameter). However, anything going beyond that does not sound
justifiable since we do not provide configuration options for any other
parameters (like supported rate sets) either for this type of low-level
radio parameters in wpa_supplicant.

-- 
Jouni Malinen                                            PGP id EFC895FA


More information about the HostAP mailing list