Re: [PATCH v2] brcmfmac: add support for CQM RSSI notifications

On 1/15/2021 3:51 PM, Andrew Zaborowski wrote:

On Fri, 15 Jan 2021 at 15:12, Arend Van Spriel
[off-list ref] wrote:>

quoted

+ Johannes
- netdevs

On 1/14/2021 5:36 PM, 'Alvin Šipraga' via BRCM80211-DEV-LIST,PDL wrote:

quoted

Add support for CQM RSSI measurement reporting and advertise the
NL80211_EXT_FEATURE_CQM_RSSI_LIST feature. This enables a userspace
supplicant such as iwd to be notified of changes in the RSSI for roaming
and signal monitoring purposes.

The more I am looking into this API the less I understand it or at least
it raises a couple of questions. Looking into nl80211_set_cqm_rssi() [1]
two behaviors are supported: 1) driver is provisioned with a threshold
and hysteresis, or 2) driver is provisioned with high and low threshold.

Right.

quoted

The second behavior is used when the driver advertises
NL80211_EXT_FEATURE_CQM_RSSI_LIST *and* user-space provides more than
one RSSI threshold.

Or, when the driver doesn't implement set_cqm_rssi_config (the old
method).  So the driver can stop supporting set_cqm_rssi_config when
it implements set_cqm_rssi_range_config.

Argh. Totally overlooked these were two different callbacks. In that 
case it is easy to determine what is being requested.

Thanks,
Arend