Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Sender: wgong=codeaurora.org@mg.codeaurora.org
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII;
 format=flowed
Content-Transfer-Encoding: 7bit
Date:   Fri, 13 Aug 2021 16:13:24 +0800
From:   Wen Gong <wgong@codeaurora.org>
To:     Johannes Berg <johannes@sipsolutions.net>
Cc:     ath11k@lists.infradead.org, linux-wireless@vger.kernel.org
Subject: Re: [PATCH 9/9] mac80211: save transmit power envelope element and
 power constraint
In-Reply-To: <38e7d9d2eebafa7245a36a0a0396094526eb3efd.camel@sipsolutions.net>
References: <20210517201932.8860-1-wgong@codeaurora.org>
 <20210517201932.8860-10-wgong@codeaurora.org>
 (sfid-20210517_222034_029448_A9A89D57)
 <d9491db4ece67ac78eb39a1078b91a106770fbb0.camel@sipsolutions.net>
 <1126f8d996e895ae048092b3f8aad19b@codeaurora.org>
 <38e7d9d2eebafa7245a36a0a0396094526eb3efd.camel@sipsolutions.net>
Message-ID: <bdbef7e30bf8d84049cd60a6350836e1@codeaurora.org>
User-Agent: Roundcube Webmail/1.3.9
Precedence: bulk

On 2021-08-13 15:19, Johannes Berg wrote:
> On Fri, 2021-07-30 at 18:47 +0800, Wen Gong wrote:
>> 
>> > And then two more questions:
>> >
>> > 1) Could this information change? Should we track it in beacons?
>> >
>> 
>> The information is from AP side, it should be not changed untill the 
>> AP
>> restart.
>> If someone want to change configure of AP, the AP should restart and
>> then take effect by my understand.
>> Is it have some case for this information change?
> 
> No, I guess that's fine then, I just didn't know.
> 
>> > 2) Should we at least check it again from the protected beacon or such
>> > after association, so we don't blindly trust the probe response or
>> > beacon (received during scan, not validated) at least when BIGTK is in
>> > use?
>> 
>> May we add support for BIGTK in future with another patch?
> 
> We already have BIGTK support in mac80211, so if we don't do that now
> we're almost certainly not going to do it, so I'd really prefer if you
> did it here, or if a separate patch still did it now.
> 
>> The info(pwr_reduction and tx_pwr_env) is used by lower driver such as
>> ath11k.
> 
> Sure.
> 
>> If the info changed after association, then how to notify lower 
>> driver?
>> Do it like below in ieee80211_rx_mgmt_beacon()?
>> And use BSS_CHANGED_TXPOWER or a new enum in ieee80211_bss_change?
> 
> Yeah, dunno. Are the drivers assuming now it's set once you get to
> associated state?

yes, driver need this info while associate process.

> 
> johannes