wifi: mt76: mt792x: stop USB register access after bus hang

Mark the mt792x USB bus hung on the first control timeout and switch
register access to no-op bus ops. Each failed vendor request may spend
up to MT_VEND_REQ_MAX_RETRY * MT_VEND_REQ_TOUT_MS, about 3 seconds, and
teardown/reset paths can keep issuing such requests after the device has
stopped responding.

Also skip the USB WFSYS reset path after bus_hung is set, since it uses
UHW vendor requests as well.

mt7925u 1-2:1.3: vendor request req:63 off:0018 failed:-110
mt7925u 1-2:1.3: vendor request req:63 off:0018 failed:-110
mt7925u 1-2:1.3: vendor request req:63 off:0018 failed:-110
mt7925u 1-2:1.3: vendor request req:63 off:0018 failed:-110
mt7925u 1-2:1.3: vendor request req:63 off:0018 failed:-110

Avoid repeating those register reads after the bus is known to be hung by
switching register access to no-op handlers.

Fixes: 0d2afe09fa ("mt76: mt7921: add mt7921u driver")
Fixes: c948b5da6b ("wifi: mt76: mt7925: add Mediatek Wi-Fi7 driver for mt7925 chips")
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Link: https://patch.msgid.link/20260613224131.2396026-4-sean.wang@kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>
This commit is contained in:
Sean Wang 2026-06-13 17:41:28 -05:00 • committed by Felix Fietkau
commit e137e5fd24
3 changed files with 90 additions and 13 deletions