[PATCH v4 00/21] wifi: mt76: mt7925/mt7921: stability and MLO fixes

[Zac]

This series addresses stability issues in the mt7925 (WiFi 7) and mt7921
drivers, focusing on NULL pointer dereferences, mutex protection, and
MLO (Multi-Link Operation) handling.

Changes since v3:
- Added mt7921 driver fixes (patches 18-19) to address mutex handling
  issues that also affected the older driver
- Fixed mutex deadlocks in mt7921 suspend paths - the mutex was being
  acquired inside functions that were already called with mutex held
- Added mt76 core fix for list corruption in mt76_wcid_cleanup (patch 20)
  that caused crashes during suspend/resume cycles
- Added fix for BA session teardown during beacon loss (patch 21) which
  was causing mac80211 WARN in __ieee80211_stop_tx_ba_session - reported
  by Sean Wang

The mt7921 mutex fixes (patches 18-19) correct improper mutex nesting
where mt7921_roc_abort_sync() and mt7921_set_runtime_pm() were acquiring
the mutex internally, but were called from paths that already held it
(e.g., mt7921_mac_sta_remove via mt76_sta_remove, suspend handlers).

The list corruption fix (patch 20) addresses a bug where mt76_wcid_cleanup()
wasn't removing wcid entries from sta_poll_list before mt76_reset_device()
reinitialized the master list, leaving stale pointers.

The BA session fix (patch 21) makes the ieee80211_stop_tx_ba_cb_irqsafe()
callback unconditional in IEEE80211_AMPDU_TX_STOP_CONT handling - the MCU
command may fail during beacon loss but mac80211 must still be notified
to complete the session teardown.

More notes in https://github.com/zbowling/mt7925

Tested on MT7925 (RZ616) with kernel 6.18.5.

Zac Bowling (21):
  wifi: mt76: mt7921: fix missing mutex protection in multiple paths
  wifi: mt76: mt7921: fix mutex deadlocks in multiple paths
  wifi: mt76: fix list corruption in mt76_wcid_cleanup
  wifi: mt76: mt7925: fix BA session teardown during beacon loss
  wifi: mt76: mt7925: fix NULL pointer dereference in vif iteration
  wifi: mt76: mt7925: fix missing mutex protection in reset and ROC
    abort
  wifi: mt76: mt7925: fix missing mutex protection in runtime PM and MLO
    PM
  wifi: mt76: mt7925: add NULL checks in MCU STA TLV functions
  wifi: mt76: mt7925: add NULL checks for link_conf and mlink in main.c
  wifi: mt76: mt7925: add error handling for AMPDU MCU commands
  wifi: mt76: mt7925: add error handling for BSS info MCU command in
    sta_add
  wifi: mt76: mt7925: add error handling for BSS info in key setup
  wifi: mt76: mt7925: add NULL checks in MLO link and chanctx functions
  wifi: mt76: mt792x: fix NULL pointer dereference in TX path
  wifi: mt76: mt7925: add lockdep assertions for mutex verification
  wifi: mt76: mt7925: fix key removal failure during MLO roaming
  wifi: mt76: mt7925: fix kernel warning in MLO ROC setup
  wifi: mt76: mt7925: add NULL checks for MLO link pointers in MCU
    functions
  wifi: mt76: mt792x: fix firmware reload failure after previous load
    crash
  wifi: mt76: mt7925: add mutex protection in resume path
  wifi: mt76: mt7925: add NULL checks in link station and TX queue setup

 drivers/net/wireless/mediatek/mt76/mac80211.c |  10 ++
 .../net/wireless/mediatek/mt76/mt7921/mac.c   |   2 +
 .../net/wireless/mediatek/mt76/mt7921/main.c  |   8 ++
 .../net/wireless/mediatek/mt76/mt7921/pci.c   |   2 +
 .../net/wireless/mediatek/mt76/mt7921/sdio.c  |   2 +
 .../net/wireless/mediatek/mt76/mt7925/mac.c   |   8 ++
 .../net/wireless/mediatek/mt76/mt7925/main.c  | 125 ++++++++++++++----
 .../net/wireless/mediatek/mt76/mt7925/mcu.c   |  48 +++++--
 .../net/wireless/mediatek/mt76/mt7925/pci.c   |   4 +
 .../net/wireless/mediatek/mt76/mt792x_core.c  |  27 +++-
 10 files changed, 203 insertions(+), 33 deletions(-)

-- 
2.52.0