On Thu, Feb 23, 2012 at 7:14 AM, Paul Stewart [off-list ref] wrote:

On Thu, Feb 23, 2012 at 6:59 AM, Johannes Berg
[off-list ref] wrote:

quoted

On Thu, 2012-02-23 at 06:53 -0800, Sam Leffler wrote:

quoted

On Thu, Feb 23, 2012 at 5:39 AM, Johannes Berg
[off-list ref] wrote:

quoted

On Mon, 2012-02-20 at 21:25 -0800, Paul Stewart wrote:

quoted

When regulatory information changes our HT behavior (e.g,
when we get a country code from the AP we have just associated
with), we should use this information to change the power with
which we transmit, and what channels we transmit.  Sometimes
the channel parameters we derive from regulatory information
contradicts the parameters we used in association.  For example,
we could have associated specifying HT40, but the regulatory
rules we apply may forbid HT40 operation.

In the situation above, we should reconfigure ourselves to
transmit in HT20 only, however it makes no sense for us to
disable receive in HT40, since if we associated with these
parameters, the AP has every reason to expect we can and
will receive packets this way.  The code in mac80211 does
not have the capability of sending the appropriate action
frames to signal a change in HT behaviour so the AP has
no clue we can no longer receive frames encoded this way.
In some broken AP implementations, this can leave us
effectively deaf if the AP never retries in lower HT rates.

This change breaks up the channel_type parameter in the
ieee80211_enable_ht function into a separate receive and
transmit part.  It honors the channel flags set by regulatory
in order to configure the rate control algorithm, but uses
the capability flags to configure the channel on the radio,
since these were used in association to set the AP's transmit
rate.

Quite the stupid APs, obviously ...

Actually the AP is operating correctly (modulo the question of whether
HT40 may be used in kr).

Ah, yes. I was thinking the AP was actually saying you can't use 40 MHz,
but it's obviously just saying that you're in KR and our database says
you then can't use 40 Mhz...

More succinctly, Sam is posing the possibility that a STA we should
ignore regulatory on TX as well as RX in this situation, since the AP
clearly negotiated HT40 with us.

If the AP was right and we were allowed to use this that'd be fine but
consider the case where the AP is wrong, they'd we'd be doing the
wrong thing. If the AP believes HT40 is allowed but our wireless-regdb
disagrees we trust our wireless-regdb more, by design.

Did I understand your question correctly?

  Luis