diff mbox series

[v2] ath11k: Increment pending_mgmt_tx count before tx send invoke

Message ID 1635168282-8845-1-git-send-email-quic_ppranees@quicinc.com (mailing list archive)
State Accepted
Commit c0b0d2e87d91ce283c8766b4b3c2ec9ac90ebf96
Delegated to: Kalle Valo
Headers show
Series [v2] ath11k: Increment pending_mgmt_tx count before tx send invoke | expand

Commit Message

P Praneesh Oct. 25, 2021, 1:24 p.m. UTC 
There is a race condition whereby the tx completion handler can be invoked
before the 'num_pending_mgmt_tx" count is incremented. If that occurs, we
could get warning trace indicating that 'num_pending_mgmt_tx' is 0 (because
it was not yet incremented). Ideally, this trace should be seen only if
mgmt tx has not happened but tx completion is received, and it is not
expected in this race condition.

Tested-on: QCN9074 hw1.0 PCI WLAN.HK.2.4.0.1-01386-QCAHKSWPL_SILICONZ-1

Co-developed-by: Lavanya Suresh <lavaks@codeaurora.org>
Signed-off-by: Lavanya Suresh <lavaks@codeaurora.org>
Signed-off-by: P Praneesh <quic_ppranees@quicinc.com>
---
v2: - corrected signed off detail.
---
 drivers/net/wireless/ath/ath11k/mac.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Kalle Valo Nov. 15, 2021, 9:26 a.m. UTC | #1 
P Praneesh <quic_ppranees@quicinc.com> wrote:

> There is a race condition whereby the tx completion handler can be invoked
> before the 'num_pending_mgmt_tx" count is incremented. If that occurs, we
> could get warning trace indicating that 'num_pending_mgmt_tx' is 0 (because
> it was not yet incremented). Ideally, this trace should be seen only if
> mgmt tx has not happened but tx completion is received, and it is not
> expected in this race condition.
> 
> Tested-on: QCN9074 hw1.0 PCI WLAN.HK.2.4.0.1-01386-QCAHKSWPL_SILICONZ-1
> 
> Co-developed-by: Lavanya Suresh <lavaks@codeaurora.org>
> Signed-off-by: Lavanya Suresh <lavaks@codeaurora.org>
> Signed-off-by: P Praneesh <quic_ppranees@quicinc.com>
> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

Patch applied to ath-next branch of ath.git, thanks.

c0b0d2e87d91 ath11k: Increment pending_mgmt_tx count before tx send invoke
diff mbox series

Patch

diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index 1cc5560..56f3208 100644
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -5048,13 +5048,15 @@  static void ath11k_mgmt_over_wmi_tx_work(struct work_struct *work)
 		arvif = ath11k_vif_to_arvif(skb_cb->vif);
 		if (ar->allocated_vdev_map & (1LL << arvif->vdev_id) &&
 		    arvif->is_started) {
+			atomic_inc(&ar->num_pending_mgmt_tx);
 			ret = ath11k_mac_mgmt_tx_wmi(ar, arvif, skb);
 			if (ret) {
+				if (atomic_dec_if_positive(&ar->num_pending_mgmt_tx) < 0)
+					WARN_ON_ONCE(1);
+
 				ath11k_warn(ar->ab, "failed to tx mgmt frame, vdev_id %d :%d\n",
 					    arvif->vdev_id, ret);
 				ieee80211_free_txskb(ar->hw, skb);
-			} else {
-				atomic_inc(&ar->num_pending_mgmt_tx);
 			}
 		} else {
 			ath11k_warn(ar->ab,