MT7612EN Constant hardware restart requested on b22977c

When this happens, all wifi traffic stops for multiple seconds while the hardware restarts
Chip: MT7612EN
Device: Xiaomi MiWiFi 4A gigabit edition

Using three of these devices as AP-repeaters with the backhaul on the same radio in WDS mode. All three are experiencing the same issue to differing degrees, some only have the message printed once per hour, others multiple times per minute. Frequency seems to depend on how many clients are connected and active. The device the log below was from a quiet AP with only 2 clients connected. If it matters, the other side of the backhaul is an Archer C7 v2 with a QCA9880-BR4A radio.

All of the devices are running the latest OpenWrt snapshot which is using this master branch at commit ID b22977c

Dmesg output follows:

[ 1105.247542] mt76x2e 0000:01:00.0: Firmware Version: 0.0.00
[ 1105.253078] mt76x2e 0000:01:00.0: Build: 1
[ 1105.257250] mt76x2e 0000:01:00.0: Build Time: 201507311614____
[ 1105.278354] mt76x2e 0000:01:00.0: Firmware running!
[ 1105.286566] ieee80211 phy1: Hardware restart was requested
[ 2382.541609] mt76x2e 0000:01:00.0: MCU message 31 (seq 6) timed out
[ 2382.586767] mt76x2e 0000:01:00.0: Firmware Version: 0.0.00
[ 2382.592296] mt76x2e 0000:01:00.0: Build: 1
[ 2382.596478] mt76x2e 0000:01:00.0: Build Time: 201507311614____
[ 2382.617593] mt76x2e 0000:01:00.0: Firmware running!
[ 2382.625861] ieee80211 phy1: Hardware restart was requested
[ 2570.690347] mt76x2e 0000:01:00.0: Firmware Version: 0.0.00
[ 2570.695877] mt76x2e 0000:01:00.0: Build: 1
[ 2570.700035] mt76x2e 0000:01:00.0: Build Time: 201507311614____
[ 2570.721149] mt76x2e 0000:01:00.0: Firmware running!
[ 2570.729397] ieee80211 phy1: Hardware restart was requested
[ 3302.287051] mt76x2e 0000:01:00.0: Firmware Version: 0.0.00
[ 3302.292558] mt76x2e 0000:01:00.0: Build: 1
[ 3302.296706] mt76x2e 0000:01:00.0: Build Time: 201507311614____
[ 3302.317843] mt76x2e 0000:01:00.0: Firmware running!
[ 3302.330030] ieee80211 phy1: Hardware restart was requested
[ 3326.257359] mt76x2e 0000:01:00.0: MCU message 31 (seq 3) timed out
[ 3326.302482] mt76x2e 0000:01:00.0: Firmware Version: 0.0.00
[ 3326.307988] mt76x2e 0000:01:00.0: Build: 1
[ 3326.312155] mt76x2e 0000:01:00.0: Build Time: 201507311614____
[ 3326.333352] mt76x2e 0000:01:00.0: Firmware running!
[ 3326.341610] ieee80211 phy1: Hardware restart was requested

The issue names no source file or test; start by tracing the mt76x2e firmware restart path associated with the reported MCU message 31 timeouts. Reproduce the behavior with WDS backhaul and varying client activity, then use the dmesg sequence to validate that the repeated hardware restarts no longer occur.