diff options
| author | Sheroz Juraev <goodmartiandev@gmail.com> | 2026-03-15 13:12:21 +0500 |
|---|---|---|
| committer | Miri Korenblit <miriam.rachel.korenblit@intel.com> | 2026-05-16 23:31:25 +0300 |
| commit | 2becb38a3e217ef2b2f42fddd7db7a25905ec291 (patch) | |
| tree | 84f12f7eda0f3e9a8018e7e0045ecd9be16ed479 | |
| parent | 92cee08dc4f00e77fd1317e4343c5d458b0abab7 (diff) | |
wifi: iwlwifi: mld: stop TX during firmware restart
When iwlwifi firmware crashes (e.g., NMI_INTERRUPT_UNKNOWN on Intel
BE201/Wi-Fi 7), iwl_mld_nic_error() sets mld->fw_status.in_hw_restart
to true. However, iwl_mld_tx_from_txq() does not check this flag before
dequeuing frames from mac80211 and pushing them to the transport layer.
Since the firmware is dead, iwl_trans_tx() returns -EIO for each frame,
which then gets freed immediately. Under high-throughput conditions
(e.g., Tailscale UDP traffic or active SSH sessions), this creates a
tight dequeue-send-fail-free loop that wastes CPU cycles and generates
rapid skb allocation churn, leading to memory pressure from slab
fragmentation.
The RX path already has this guard (iwl_mld_rx_mpdu checks
in_hw_restart at rx.c:1906), and so does the TXQ allocation worker
(iwl_mld_add_txqs_wk at tx.c:156). Add the same guard to
iwl_mld_tx_from_txq() to stop all TX during firmware restart.
Frames left in mac80211's TXQs are naturally drained after restart
completes, when queue reallocation triggers iwl_mld_tx_from_txq()
via iwl_mld_add_txq_list(), or when new upper-layer traffic invokes
wake_tx_queue.
Tested on ASUS Zenbook 14 UX3405CA with Intel BE201 (Wi-Fi 7) on
kernel 6.19.5 where the firmware crashes approximately every 10-15
minutes under Tailscale traffic.
Fixes: d1e879ec600f ("wifi: iwlwifi: add iwlmld sub-driver")
Cc: stable@vger.kernel.org
Signed-off-by: Sheroz Juraev <goodmartiandev@gmail.com>
Link: https://patch.msgid.link/20260315081221.2678478-1-goodmartiandev@gmail.com
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
| -rw-r--r-- | drivers/net/wireless/intel/iwlwifi/mld/tx.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/net/wireless/intel/iwlwifi/mld/tx.c b/drivers/net/wireless/intel/iwlwifi/mld/tx.c index 094a28f75559..0bcb1ae69468 100644 --- a/drivers/net/wireless/intel/iwlwifi/mld/tx.c +++ b/drivers/net/wireless/intel/iwlwifi/mld/tx.c @@ -974,6 +974,16 @@ void iwl_mld_tx_from_txq(struct iwl_mld *mld, struct ieee80211_txq *txq) u8 zero_addr[ETH_ALEN] = {}; /* + * Don't transmit during firmware restart. The firmware is dead, + * so iwl_trans_tx() would return -EIO for each frame. Avoid the + * overhead of dequeuing from mac80211 only to immediately free + * the skbs, and the potential memory pressure from rapid skb + * allocation churn during high-throughput restart scenarios. + */ + if (unlikely(mld->fw_status.in_hw_restart)) + return; + + /* * No need for threads to be pending here, they can leave the first * taker all the work. * |