[PATCH] mt76: Enable NL80211_EXT_FEATURE_CQM_RSSI_LIST

[PATCH] mt76: Enable NL80211_EXT_FEATURE_CQM_RSSI_LIST

[Kristian Evensen]

Enable the use of CQM with mt76-devices.

Signed-off-by: Kristian Evensen <kristian.evensen@gmail.com>
---
 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);
+
 	wiphy->available_antennas_tx = dev->antenna_mask;
 	wiphy->available_antennas_rx = dev->antenna_mask;
 
-- 
2.14.1

Re: [PATCH] mt76: Enable NL80211_EXT_FEATURE_CQM_RSSI_LIST

[Kalle Valo]

Kristian Evensen <kristian.evensen@gmail.com> writes:

> Enable the use of CQM with mt76-devices.
>
> Signed-off-by: Kristian Evensen <kristian.evensen@gmail.com>
> ---
>  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?

-- 
Kalle Valo

Re: [PATCH] mt76: Enable NL80211_EXT_FEATURE_CQM_RSSI_LIST

[Arend van Spriel]

On 8/12/2018 8:14 PM, Kalle Valo wrote:
> Kristian Evensen <kristian.evensen@gmail.com> writes:
>
>> Enable the use of CQM with mt76-devices.
>>
>> Signed-off-by: Kristian Evensen <kristian.evensen@gmail.com>
>> ---
>>   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

Re: [PATCH] mt76: Enable NL80211_EXT_FEATURE_CQM_RSSI_LIST

[Kristian Evensen]

Hi Kalle & Arnd,
On Sun, Aug 12, 2018 at 8:44 PM Arend van Spriel
<arend.vanspriel@broadcom.com> wrote:
> > 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:

Thank you very much for your feedback. My commit message should have
been more detailed, sorry about that. I have checked that the flag
works as intended with mt7602-, mt7603- and mt7612-based wifi cards. I
have not had the opportunity to test with any of the recently added
USB devices, as I don't have access to any of those.

In order to test the flag, I wrote a small program which subscribes to
the CQM-multicast group, passes an RSSI threshold-list to the kernel
and logs the received CQM-events. I then disconnected and connected
the wifi-antennas of the different cards. My threshold list was {-70,
-60, -50, -40} and while unscrewing the antenna I received multiple
below-events. When I attached the antenna again, I received multiple
above-events. As an example, here is the log when I tested with mt7612
(singal level when starting was ~-48 dBm):

Requested nl80211 generic netlink id
nl80211 has generic netlink id: 23
mlme ID is 5
Added socket to mlme group
Sent NL80211_CMD_SET_CQM
No error
Wifi (idx 18) went below threshold. RSSI -52
Wifi (idx 18) went above threshold. RSSI -49
Wifi (idx 18) went below threshold. RSSI -52
Wifi (idx 18) went below threshold. RSSI -62
Wifi (idx 18) went above threshold. RSSI -59
Wifi (idx 18) went above threshold. RSSI -49

Based on how I interpret the output and my understanding of how CQM +
RSSI_LIST works, this output shows that mt76 works fine with
NL80211_EXT_FEATURE_CQM_RSSI_LIST (at least for my cards). The list
was interpreted and handled correctly, as I received events when the
RSSI passed different thresholds in my list (-50, -60).

BR,
Kristian