[PATCH v4 3/6] mac80211: check if HT40+/- is allowed before sending assoc

[PATCH v4 3/6] mac80211: check if HT40+/- is allowed before sending assoc

[Luis R. Rodriguez]

We weren't checking this at all.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
---

Another mistake on my part, caught by sujith -- we were disabling HT
completley if NOHT40 was set, we now stick to HT20 when HT40 is not
set.

 net/mac80211/ht.c |   11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/net/mac80211/ht.c b/net/mac80211/ht.c
index 4e3c72f..9c4faa4 100644
--- a/net/mac80211/ht.c
+++ b/net/mac80211/ht.c
@@ -119,13 +119,18 @@ u32 ieee80211_enable_ht(struct ieee80211_sub_if_data *sdata,
 
 		if (!(ap_ht_cap_flags & IEEE80211_HT_CAP_40MHZ_INTOLERANT) &&
 		    (sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) &&
-		    (hti->ht_param & IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
+		    (hti->ht_param & IEEE80211_HT_PARAM_CHAN_WIDTH_ANY) &&
+		    !(local->hw.conf.channel->flags & IEEE80211_CHAN_NO_HT40)) {
 			switch(hti->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
 			case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
-				channel_type = NL80211_CHAN_HT40PLUS;
+				if (!(local->hw.conf.channel->flags &
+				    IEEE80211_CHAN_NO_HT40PLUS))
+					channel_type = NL80211_CHAN_HT40PLUS;
 				break;
 			case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
-				channel_type = NL80211_CHAN_HT40MINUS;
+				if (!(local->hw.conf.channel->flags &
+				    IEEE80211_CHAN_NO_HT40MINUS))
+					channel_type = NL80211_CHAN_HT40MINUS;
 				break;
 			}
 		}
-- 
1.5.6.4

Re: [PATCH v4 3/6] mac80211: check if HT40+/- is allowed before sending assoc

[Johannes Berg]

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On Thu, 2009-03-19 at 02:41 -0400, Luis R. Rodriguez wrote:
> We weren't checking this at all.

The question is whether we really want that. In other places, we trust
the AP, why not here as well?

johannes

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Re: [PATCH v4 3/6] mac80211: check if HT40+/- is allowed before sending assoc

[Luis R. Rodriguez]

On Fri, Mar 20, 2009 at 03:48:56AM -0700, Johannes Berg wrote:
> On Thu, 2009-03-19 at 02:41 -0400, Luis R. Rodriguez wrote:
> > We weren't checking this at all.
> 
> The question is whether we really want that. In other places, we trust
> the AP, why not here as well?

Its not about trust its also about if it will logistically make sense, for
example you simply cannot use HT40- on channel 11 if yuo don't have
a channel 7. The NO_HT40- would indicate this to us so we don't bother.
The example I give is lousy as its not something that would occur usually
but with 5 GHz and regulatory rules changing things could be a bit
different.

> 
> johannes


  Luis

Re: [PATCH v4 3/6] mac80211: check if HT40+/- is allowed before sending assoc

[Johannes Berg]

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On Fri, 2009-03-20 at 07:29 -0700, Luis R. Rodriguez wrote:
> On Fri, Mar 20, 2009 at 03:48:56AM -0700, Johannes Berg wrote:
> > On Thu, 2009-03-19 at 02:41 -0400, Luis R. Rodriguez wrote:
> > > We weren't checking this at all.
> > 
> > The question is whether we really want that. In other places, we trust
> > the AP, why not here as well?
> 
> Its not about trust its also about if it will logistically make sense, for
> example you simply cannot use HT40- on channel 11 if yuo don't have
> a channel 7. The NO_HT40- would indicate this to us so we don't bother.
> The example I give is lousy as its not something that would occur usually
> but with 5 GHz and regulatory rules changing things could be a bit
> different.

Yeah, good point. That's why we need to disassoc from the AP if we
definitely cannot support it -- we cannot change the APs opinion of our
HT40 capabilities. Of course, when we start out not supporting it we can
tell it we don't do HT40.

johannes

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