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
Date: Tue, 03 Aug 2021 16:53:55 +0800 [thread overview]
Message-ID: <270e3bd0143564b2e2ec6c359897a507@codeaurora.org> (raw)
In-Reply-To: <1126f8d996e895ae048092b3f8aad19b@codeaurora.org>
Hi johannes,
Could you see my answer below?
please feel free to point out the mistakes :)
On 2021-07-30 18:47, Wen Gong wrote:
> On 2021-07-23 17:38, Johannes Berg wrote:
>> On Mon, 2021-05-17 at 16:19 -0400, Wen Gong wrote:
>>>
>>> + if (is_6ghz) {
>>> + struct ieee802_11_elems elems;
>>> + struct ieee80211_bss_conf *bss_conf;
>>> + u8 i, n;
>>> +
>>> + ieee802_11_parse_elems(ies->data, ies->len, false, &elems,
>>> + NULL, NULL);
>>> + bss_conf = &sdata->vif.bss_conf;
>>> + bss_conf->pwr_reduction = 0;
>>> + if (elems.pwr_constr_elem)
>>> + bss_conf->pwr_reduction = *elems.pwr_constr_elem;
>>> +
>>> + memset(bss_conf->tx_pwr_env, 0, sizeof(bss_conf->tx_pwr_env));
>>> + bss_conf->tx_pwr_env_num = elems.tx_pwr_env_num;
>>> + n = min_t(u8, elems.tx_pwr_env_num,
>>> + ARRAY_SIZE(elems.tx_pwr_env));
>>
>> If anything, that min_t would make sense only if you were actually
>> using
>> ARRAY_SIZE(bss_conf->tx_pwr_env), but like this it's quite pointless,
>> just checking again if the element parsing was internally consistent?
>>
>> I'd probably remove it and throw in a
>>
>> BUILD_BUG_ON(ARRAY_SIZE(bss_conf->tx_pwr_env) !=
>> ARRAY_SIZE(elems.tx_pwr_env));
>>
>> instead.
>>
>>> + for (i = 0; i < n; i++)
>>> + memcpy(&bss_conf->tx_pwr_env[i], elems.tx_pwr_env[i],
>>> + elems.tx_pwr_env_len[i]);
>>
>> You also never validated that the element wasn't too long!
>>
> will change it.
>>
>> If you connect to 6 Ghz with this, and then again to another AP that
>> doesn't, you'll have it stuck at the old values. You need to reset at
>> some point (during disconnect).
>>
> will change to reset it in ieee80211_prep_channel outside is_6ghz{}.
> Then it will be reset for each connection.
>> 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?
>
>
>> 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?
> The info(pwr_reduction and tx_pwr_env) is used by lower driver such as
> ath11k.
> 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?
>
> ieee80211_rx_mgmt_beacon{
> changed |= ieee80211_handle_pwr_constr(sdata, chan, mgmt,
> elems.country_elem,
> elems.country_elem_len,
> elems.pwr_constr_elem,
> elems.cisco_dtpc_elem);
>
> ieee80211_bss_info_change_notify(sdata, changed);
> }
>
>>
>> johannes
--
ath11k mailing list
ath11k@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/ath11k
next prev parent reply other threads:[~2021-08-03 8:54 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-17 20:19 [PATCH 0/9] cfg80211/mac80211: Add support for 6GHZ STA for various modes : LPI, SP and VLP Wen Gong
2021-05-17 20:19 ` [PATCH 1/9] cfg80211: add power type definition for 6G Hz Wen Gong
2021-07-23 9:22 ` Johannes Berg
2021-05-17 20:19 ` [PATCH 2/9] mac80211: add definition of regulatory info in 6G Hz operation information Wen Gong
2021-05-17 20:19 ` [PATCH 3/9] mac80211: add parse " Wen Gong
2021-07-23 9:23 ` Johannes Berg
2021-05-17 20:19 ` [PATCH 4/9] cfg80211: add definition for 6G power spectral density(psd) Wen Gong
2021-07-23 9:24 ` Johannes Berg
2021-07-30 10:00 ` Wen Gong
2021-05-17 20:19 ` [PATCH 5/9] cfg80211: save power spectral density(psd) of regulatory rule Wen Gong
2021-07-23 9:27 ` Johannes Berg
2021-07-30 10:06 ` Wen Gong
2021-05-17 20:19 ` [PATCH 6/9] mac80211: add definition for transmit power envelope element Wen Gong
2021-07-23 9:29 ` Johannes Berg
2021-07-23 9:31 ` Johannes Berg
2021-07-30 10:27 ` Wen Gong
2021-05-17 20:19 ` [PATCH 7/9] mac80211: add parse " Wen Gong
2021-07-23 9:33 ` Johannes Berg
2021-07-30 10:16 ` Wen Gong
2021-05-17 20:19 ` [PATCH 8/9] mac80211: add transmit power envelope element and power constraint in bss_conf Wen Gong
2021-07-23 9:33 ` Johannes Berg
2021-05-17 20:19 ` [PATCH 9/9] mac80211: save transmit power envelope element and power constraint Wen Gong
2021-07-23 9:38 ` Johannes Berg
2021-07-30 10:47 ` Wen Gong
2021-08-03 8:53 ` Wen Gong [this message]
2021-08-13 7:19 ` Johannes Berg
2021-08-13 7:25 ` Johannes Berg
2021-08-13 8:47 ` Wen Gong
2021-08-13 8:53 ` Johannes Berg
2021-08-13 9:16 ` Wen Gong
2021-08-13 10:11 ` Johannes Berg
2021-08-13 10:29 ` Wen Gong
2021-08-13 8:13 ` Wen Gong
2021-05-25 10:04 ` [PATCH 0/9] cfg80211/mac80211: Add support for 6GHZ STA for various modes : LPI, SP and VLP Wen Gong
2021-06-15 8:52 ` Wen Gong
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=270e3bd0143564b2e2ec6c359897a507@codeaurora.org \
--to=wgong@codeaurora.org \
--cc=ath11k@lists.infradead.org \
--cc=johannes@sipsolutions.net \
--cc=linux-wireless@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).