Jouni,
Does hostpad disable 5GHz channels intentionally? For regulation reason?
Thanks,
-yi
-------- Forwarded Message --------
From: Johannes Berg <[email protected]>
To: Zhu Yi <[email protected]>
Cc: Jouni Malinen <[email protected]>, [email protected]
Subject: Re: hostapd with mac80211 progress
Date: Tue, 04 Mar 2008 11:00:22 +0100
> Well, it (HOSTAPD_CHAN_W_SCAN) was removed somewhere after
> driver_nl80211.c set it. I think it's a hostapd bug. Please take a look
> at the hostapd_get_hw_features() function:
>
>
> if ((feature->mode == HOSTAPD_MODE_IEEE80211G ||
> feature->mode == HOSTAPD_MODE_IEEE80211B) &&
> feature->channels[j].chan >= 1 &&
> feature->channels[j].chan <= 11) {
> power_level = 20;
> feature->channels[j].flag |=
> HOSTAPD_CHAN_W_SCAN;
> } else
> feature->channels[j].flag &=
> ~HOSTAPD_CHAN_W_SCAN;
>
>
> Apparently, A channels all have this flag removed. What does this flag
> stand for? I assume it stands for passive scan, right?
Ah, you're on 5 GHz then? Sorry, I'm not too familiar with hostapd
internals yet. I don't think the flag stands for passive scan, I think
it pretty much used to stand for "channel is usable at all" in the
dscape stack.
johannes
On Wed, Mar 05, 2008 at 09:20:20AM +0800, Zhu Yi wrote:
> Does hostpad disable 5GHz channels intentionally? For regulation reason?
The hw_feature/channel selection code was originally using a regulatory
domain database within hostapd and that information was used to select
which channels are to be enabled. However, that code was never cleaned
up and not merged into the open source version.
I don't remember all the details anymore, but it looks like I just left
it to hardcoded 802.11g channels 1-11 only configuration. In other
words, yes, I would say that 5 GHz channels were disabled intentionally
for the time being. This will obviously need to be changed once more
suitable mechanism for regulatory domain information becomes available
(the TODO comment in the hostapd function that was mentioned in this
thread..).
--
Jouni Malinen PGP id EFC895FA