Subject: Re: [PATCH] mt76: Enable NL80211_EXT_FEATURE_CQM_RSSI_LIST

From: Arend van Spriel <arend.vanspriel-dY08KVG/lbpWk0Htik3J/[email-masked]>
Date: Sun, 12 Aug 2018 20:44:53 +0200

On 8/12/2018 8:14 PM, Kalle Valo wrote:
> Kristian Evensen <[email-masked]> writes:
>
>> Enable the use of CQM with mt76-devices.
>>
>> Signed-off-by: Kristian Evensen <[email-masked]>
>> ---
>>   drivers/net/wireless/mediatek/mt76/mac80211.c | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/drivers/net/wireless/mediatek/mt76/mac80211.c b/drivers/net/wireless/mediatek/mt76/mac80211.c
>> index 029d54bc..3eb328ff 100644
>> --- a/drivers/net/wireless/mediatek/mt76/mac80211.c
>> +++ b/drivers/net/wireless/mediatek/mt76/mac80211.c
>> @@ -305,6 +305,8 @@ int mt76_register_device(struct mt76_dev *dev, bool vht,
>>
>>   	wiphy->features |= NL80211_FEATURE_ACTIVE_MONITOR;
>>
>> +	wiphy_ext_feature_set(wiphy, NL80211_EXT_FEATURE_CQM_RSSI_LIST);
>
> So have you tested this and with what devices? For example, does it work
> with recently added USB devices?

I was looking into this as it looks suspicious to me. From reading the 
description of this ext_feature flag it seems this is an extention of CQM:

"""
  * @NL80211_EXT_FEATURE_CQM_RSSI_LIST: With this driver the
  *	%NL80211_ATTR_CQM_RSSI_THOLD attribute accepts a list of zero or more
  *	RSSI threshold values to monitor rather than exactly one threshold.
"""

Also looking at mt76x2_bss_info_changed() it does not handle 
BSS_CHANGED_CQM so I doubt it has support for it (yet). The driver does 
not use IEEE80211_VIF_SUPPORTS_CQM_RSSI which is a requirement for it.

Regards,
Arend

https://elixir.bootlin.com/linux/latest/source/drivers/net/wireless/mediatek/mt76/mt76x2_main.c#L223