Re: [PATCH 2/2] ath10k: DFS Host Confirmation

[Kalle Valo <kvalo@codeaurora.org>]

Peter Oh <peter.oh@bowerswilkins.com> writes:

> On 04/30/2018 10:45 AM, Sriram R wrote:
>> In the 10.4-3.6 firmware branch there's a new DFS Host confirmation
>> feature which is advertised using WMI_SERVICE_HOST_DFS_CHECK_SUPPORT flag.
>>
>> This new features enables the ath10k host to send information to the
>> firmware on the specifications of detected radar type. This allows the
>> firmware to validate if the host's radar pattern detector unit is
>> operational and check if the radar information shared by host matches
>> the radar pulses sent as phy error events from firmware. If the check
>> fails the firmware won't allow use of DFS channels on AP mode when using
>> FCC regulatory region.
>
> What's the main reason you introduce this feature?
> What are you trying to solve with this change?

Otherwise one cannot use DFS channels on FCC regions with a firmware
from 10.4-3.6 branch.

>> @@ -3765,25 +3834,46 @@ static void ath10k_dfs_radar_report(struct ath10k *ar,
>>     	ATH10K_DFS_STAT_INC(ar, pulses_detected);
>>   -	if (!ar->dfs_detector->add_pulse(ar->dfs_detector, &pe, NULL))
>> {
>> +	if (!ar->dfs_detector->add_pulse(ar->dfs_detector, &pe, &rs)) {
>>   		ath10k_dbg(ar, ATH10K_DBG_REGULATORY,
>>   			   "dfs no pulse pattern detected, yet\n");
>>   		return;
>>   	}
>>   -radar_detected:
>> -	ath10k_dbg(ar, ATH10K_DBG_REGULATORY, "dfs radar detected\n");
>> -	ATH10K_DFS_STAT_INC(ar, radar_detected);
>> +	if ((test_bit(WMI_SERVICE_HOST_DFS_CHECK_SUPPORT, ar->wmi.svc_map)) &&
>> +	    ar->dfs_detector->region == NL80211_DFS_FCC) {
>
> I feel risky that host drivers have no way to control this new feature
> and totally rely on FW feature mask. We should have a host drivers'
> feature mask such as module param and set it false (don't use) by
> default until it proves safe to use.

This is for regulatory enforcement so it's not possible to disable the
feature from host.

-- 
Kalle Valo