What is the Maximum Beacon Interval Value that can be set for an Access Point?
Features > Power Save Modes
Answer: The hard limit for the beacon interval setting is 10,000 ms.
Explanation: From the Morse Micro Web GUI, it appears that the beacon interval can be set to 65,535 ms, however this will not work as intended. This 10,000 ms maximum beacon interval restriction was introduced in Linux Kernel version 4.9. Anyone using mac80211 version <4.9 may not observe this issue. This is not a Wifi HaLow specific issue as any Wifi component using cfg80211/mac80211 will have this restricted maximum beacon interval value.
The relevant piece of kernel code: net/wireless/nl80211.c // Question for Hamish - Is there a way to do in-line code?
int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
enum nl80211_iftype iftype, u32 beacon_int)
{
/*
* This is just a basic pre-condition check; if interface combinations
* are possible the driver must already be checking those with a call
* to cfg80211_check_combinations(), in which case we'll validate more
* through the cfg80211_calculate_bi_data() call and code in
* cfg80211_iter_combinations().
*/
if (beacon_int < 10 || beacon_int > 10000)
return -EINVAL;
return 0;
}