[PATCH v1] wifi: mt76: mt7925: Fix MCU command timeouts during module unload

[Eason Lai (賴易聖)]

On Wed, 2026-08-05 at 10:46 -0700, Devin Wittmayer wrote:
> 
> Tested this on an MT7927 here, against a reproduction I built on
> 2026-08-02 when I hit the same teardown. It fixes it.
> 
> mt7925e on 7.1.5, morrownr/mt76 at 217ee83d, which carries the
> unregister-deadlock change your Fixes tag names (openwrt
> 98c13eb564e5).
> Each cycle associates WPA2 at 2412 MHz, runs a 1400-byte ICMP flood,
> and
> rmmods with that traffic in flight, RX sampled off
> statistics/rx_packets
> immediately before the unload at 375 to 807 pps across both arms.
> Both
> arms built in the same directory, so only mt7925e and mt792x_lib
> differ
> between them.
> 
>   condition              stock                      patched
>   associated, 10 cycles  59-60 s, 19 timeouts each  0-1 s, none
>   idle, 3 cycles         9-10 s, 3 timeouts each    0 s, none
> 
> No warnings or call traces in any window on either arm.
> 
> The idle row is worth a line in the commit message: with nothing
> associated it still costs 9 to 10 seconds, so a bare rmmod does reach
> this, just small enough there to read as normal teardown.
> 
> Tested-by: Devin Wittmayer <lucid_duck at justthetip.ca>

I will update the commit message for v2 based on your suggestion.

Thanks,
Eason