2021-05-05 09:01:49

by Sebastian Gottschall

[permalink] [raw]
Subject: [PATCH] ath10k: Fix tx hanging

While running stress tests in roaming scenarios (switching ap's every 5
seconds, we discovered a issue which leads to tx hangings of exactly 5
seconds while or after scanning for new accesspoints. We found out that
this hanging is triggered by ath10k_mac_wait_tx_complete since the
empty_tx_wq was not wake when the num_tx_pending counter reaches zero.
To fix this, we simply move the wake_up call to htt_tx_dec_pending,
since this call was missed on several locations within the ath10k code.

Signed-off-by: Sebastian Gottschall <[email protected]>
---
drivers/net/wireless/ath/ath10k/htt_tx.c | 3 +++
drivers/net/wireless/ath/ath10k/txrx.c | 2 --
2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/htt_tx.c b/drivers/net/wireless/ath/ath10k/htt_tx.c
index d6b8bdcef416..b793eac2cfac 100644
--- a/drivers/net/wireless/ath/ath10k/htt_tx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_tx.c
@@ -147,6 +147,9 @@ void ath10k_htt_tx_dec_pending(struct ath10k_htt *htt)
htt->num_pending_tx--;
if (htt->num_pending_tx == htt->max_num_pending_tx - 1)
ath10k_mac_tx_unlock(htt->ar, ATH10K_TX_PAUSE_Q_FULL);
+
+ if (htt->num_pending_tx == 0)
+ wake_up(&htt->empty_tx_wq);
}

int ath10k_htt_tx_inc_pending(struct ath10k_htt *htt)
diff --git a/drivers/net/wireless/ath/ath10k/txrx.c b/drivers/net/wireless/ath/ath10k/txrx.c
index 7c9ea0c073d8..6f8b64218894 100644
--- a/drivers/net/wireless/ath/ath10k/txrx.c
+++ b/drivers/net/wireless/ath/ath10k/txrx.c
@@ -82,8 +82,6 @@ int ath10k_txrx_tx_unref(struct ath10k_htt *htt,
flags = skb_cb->flags;
ath10k_htt_tx_free_msdu_id(htt, tx_done->msdu_id);
ath10k_htt_tx_dec_pending(htt);
- if (htt->num_pending_tx == 0)
- wake_up(&htt->empty_tx_wq);
spin_unlock_bh(&htt->tx_lock);

rcu_read_lock();
--
2.31.1