linux-kernel - [PATCH ath-next 2/4] wifi: ath12k: avoid long fw

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Message-ID: <20260209030243.1530075-3-m.limarencko@yandex.ru>
Date: Mon,  9 Feb 2026 06:02:41 +0300
From: m.limarencko@...dex.ru
To: jjohnson@...nel.org
Cc: linux-wireless@...r.kernel.org,
	ath12k@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	Mikhail Limarenko <m.limarencko@...dex.ru>
Subject: [PATCH ath-next 2/4] wifi: ath12k: avoid long fw_stats waits on vdev stats hot path

From: Mikhail Limarenko <m.limarencko@...dex.ru>

Station info requests can trigger frequent VDEV stat pulls from

user space (iw/NM polling).

On affected firmware, waiting 3 seconds for fw_stats_done causes

repeated stalls and visible hitches.

Use a short timeout for VDEV_STAT requests and skip unnecessary

waits for stats types that do not need completion

synchronization.

Tested-on: QCNFA765 (WCN785x), kernel 6.18.5+deb13-amd64
Signed-off-by: Mikhail Limarenko <m.limarencko@...dex.ru>
---
 drivers/net/wireless/ath/ath12k/mac.c | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
index 095b49a..1b550e9 100644
--- a/drivers/net/wireless/ath/ath12k/mac.c
+++ b/drivers/net/wireless/ath/ath12k/mac.c
@@ -4829,6 +4829,7 @@ int ath12k_mac_get_fw_stats(struct ath12k *ar,
 {
 	struct ath12k_base *ab = ar->ab;
 	struct ath12k_hw *ah = ath12k_ar_to_ah(ar);
+	unsigned long done_timeout = 3 * HZ;
 	unsigned long time_left;
 	int ret;
 
@@ -4859,15 +4860,32 @@ int ath12k_mac_get_fw_stats(struct ath12k *ar,
 		return -ETIMEDOUT;
 	}
 
+	/* VDEV stats are queried frequently from station info paths (e.g. iw/NM).
+	 * On buggy firmware this path can timeout repeatedly and block callers for
+	 * multiple seconds; keep the hot path responsive while preserving behavior
+	 * for other stats types.
+	 */
+	if (param->stats_id & WMI_REQUEST_VDEV_STAT)
+		done_timeout = msecs_to_jiffies(200);
+
+	/* Non-vdev/bcn stats are handled in a single event. */
+	if (!(param->stats_id & (WMI_REQUEST_VDEV_STAT | WMI_REQUEST_BCN_STAT)))
+		return 0;
+
 	/* Firmware sends WMI_UPDATE_STATS_EVENTID back-to-back
 	 * when stats data buffer limit is reached. fw_stats_complete
 	 * is completed once host receives first event from firmware, but
 	 * still there could be more events following. Below is to wait
 	 * until firmware completes sending all the events.
 	 */
-	time_left = wait_for_completion_timeout(&ar->fw_stats_done, 3 * HZ);
+	time_left = wait_for_completion_timeout(&ar->fw_stats_done, done_timeout);
 	if (!time_left) {
-		ath12k_warn(ab, "time out while waiting for fw stats done\n");
+		if (param->stats_id & WMI_REQUEST_VDEV_STAT)
+			ath12k_dbg(ab, ATH12K_DBG_WMI,
+				   "time out while waiting for fw stats done (stats_id 0x%x)\n",
+				   param->stats_id);
+		else
+			ath12k_warn(ab, "time out while waiting for fw stats done\n");
 		return -ETIMEDOUT;
 	}
 
-- 
2.47.3