[PATCH 6.4 731/800] wifi: ath10k: Serialize wake_tx_queue ops

Greg Kroah-Hartman
2023-07-16T20:27:00Z

From: Alexander Wetzel <alexander@wetzel-home.de>

commit b719ebc37a1eacd4fd4f1264f731b016e5ec0c6e upstream.

Serialize the ath10k implementation of the wake_tx_queue ops.
ath10k_mac_op_wake_tx_queue() must not run concurrent since it's using
ieee80211_txq_schedule_start().

The intend of this patch is to sort out an issue discovered in the discussion
referred to by the Link tag.

I can't test it with real hardware and thus just implemented the per-ac queue
lock Felix suggested. One obvious alternative to the per-ac lock would be to
bring back the txqs_lock commit bb2edb733586 ("ath10k: migrate to mac80211 txq
scheduling") dropped.

Fixes: bb2edb733586 ("ath10k: migrate to mac80211 txq scheduling")
Reported-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/519b5bb9-8899-ae7c-4eff-f3116cdfdb56@nbd.name
CC: <stable@vger.kernel.org>
Signed-off-by: Alexander Wetzel <alexander@wetzel-home.de>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230323165527.156414-1-alexander@wetzel-home.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/wireless/ath/ath10k/core.c | 3 +++
drivers/net/wireless/ath/ath10k/core.h | 3 +++
drivers/net/wireless/ath/ath10k/mac.c | 6 ++++--
3 files changed, 10 insertions(+), 2 deletions(-)

--- a/drivers/net/wireless/ath/ath10k/core.c
+++ b/drivers/net/wireless/ath/ath10k/core.c
@@ -3634,6 +3634,9 @@ struct ath10k *ath10k_core_create(size_t
mutex_init(&ar->dump_mutex);
spin_lock_init(&ar->data_lock);

+ for (int ac = 0; ac < IEEE80211_NUM_ACS; ac++)
+ spin_lock_init(&ar->queue_lock[ac]);
+
INIT_LIST_HEAD(&ar->peers);
init_waitqueue_head(&ar->peer_mapping_wq);
init_waitqueue_head(&ar->htt.empty_tx_wq);
--- a/drivers/net/wireless/ath/ath10k/core.h
+++ b/drivers/net/wireless/ath/ath10k/core.h
@@ -1170,6 +1170,9 @@ struct ath10k {
/* protects shared structure data */
spinlock_t data_lock;

+ /* serialize wake_tx_queue calls per ac */
+ spinlock_t queue_lock[IEEE80211_NUM_ACS];
+
struct list_head arvifs;
struct list_head peers;
struct ath10k_peer *peer_map[ATH10K_MAX_NUM_PEER_IDS];
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -4732,13 +4732,14 @@ static void ath10k_mac_op_wake_tx_queue(
{
struct ath10k *ar = hw->priv;
int ret;
- u8 ac;
+ u8 ac = txq->ac;

ath10k_htt_tx_txq_update(hw, txq);
if (ar->htt.tx_q_state.mode != HTT_TX_MODE_SWITCH_PUSH)
return;

- ac = txq->ac;
+ spin_lock_bh(&ar->queue_lock[ac]);
+
ieee80211_txq_schedule_start(hw, ac);
txq = ieee80211_next_txq(hw, ac);
if (!txq)
@@ -4753,6 +4754,7 @@ static void ath10k_mac_op_wake_tx_queue(
ath10k_htt_tx_txq_update(hw, txq);
out:
ieee80211_txq_schedule_end(hw, ac);
+ spin_unlock_bh(&ar->queue_lock[ac]);
}

/* Must not be called with conf_mutex held as workers can use that also. */