[LEDE-DEV] [PATCH 2/2] mac80211.sh: Support VHT40 hw type for ibss.

[Felix Fietkau]

On 2017-01-25 14:58, Ben Greear wrote:
> 
> 
> On 01/25/2017 12:33 AM, Felix Fietkau wrote:
>> On 2017-01-20 00:08, greearb at candelatech.com wrote:
>>> From: Ben Greear <greearb at candelatech.com>
>>>
>>> This doesn't actually limit it to VHT40 rates on ath10k,
>>> it seems, but it does let it run VHT 80 rates, which
>>> seems better than disable VHT entirely.
>>>
>>> Signed-off-by: Ben Greear <greearb at candelatech.com>
>>> ---
>>>   package/kernel/mac80211/files/lib/netifd/wireless/mac80211.sh | 4 ++--
>>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/package/kernel/mac80211/files/lib/netifd/wireless/mac80211.sh b/package/kernel/mac80211/files/lib/netifd/wireless/mac80211.sh
>>> index 1fa39b8..792549a 100644
>>> --- a/package/kernel/mac80211/files/lib/netifd/wireless/mac80211.sh
>>> +++ b/package/kernel/mac80211/files/lib/netifd/wireless/mac80211.sh
>>> @@ -496,8 +496,8 @@ mac80211_setup_supplicant() {
>>>
>>>   mac80211_setup_adhoc_htmode() {
>>>   	case "$htmode" in
>>> -		VHT20|HT20) ibss_htmode=HT20;;
>>> -		HT40*|VHT40|VHT160)
>>> +		VHT20|HT20|VHT40|VHT160) ibss_htmode="$htmode";;
>>> +		HT40*)
>> Did you verify that the center channel / control channel setup is
>> correct here?
> 
> When you request VHT40, then the IBSS station is actually in VHT80 mode,
> so it certainly isn't perfect, but at least it does VHT.  I did check that
> the traffic was sniffable on channel 36 (where I configured LEDE to run).
> 
> I did not try to verify it closer than that.
It seems to me that this stuff is not supported properly by iw, so we
should not add it to the scripts either.

With ht40 the script correctly determines if the control channel has to
be above or below the center channel, based on the channel number and
the standardized allocation of channel groups.

For VHT, no such logic exists and iw doesn't even understand the VHT*
mode strings.

Feel free to re-submit something like this when iw has proper support
for it and you have a way of dealing with the center vs control channel
issue.

- Felix