[PATCH ath-next 3/8] wifi: ath12k: add TCL ring TX buffer allocation failure counter

From: Hariharan Ramanathan <[email protected]>

When ath12k_dp_tx_assign_buffer() fails, the TX path returns -ENOMEM
silently with no visibility into which traffic class is affected.
Without a counter, TX descriptor pool exhaustion is invisible during
debugging.

Add txbuf_na[] indexed by pool_id to ath12k_device_dp_tx_err_stats to
track TX descriptor pool allocation failures per traffic class and
increment it on assign failure in the TX path. Expose the per-pool
counts in debugfs under a new 'TX Descriptor Pool Alloc Failures'
section.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.6.r1-00402-QCAHKSWPL_SILICONZ-1

Signed-off-by: Hariharan Ramanathan <[email protected]>
Co-developed-by: Pardeep Kaur <[email protected]>
Signed-off-by: Pardeep Kaur <[email protected]>
---
 drivers/net/wireless/ath/ath12k/debugfs.c     | 5 +++++
 drivers/net/wireless/ath/ath12k/dp.h          | 2 ++
 drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c | 4 +++-
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath12k/debugfs.c b/drivers/net/wireless/ath/ath12k/debugfs.c
index d54995b7adb2..ec49692107a8 100644
--- a/drivers/net/wireless/ath/ath12k/debugfs.c
+++ b/drivers/net/wireless/ath/ath12k/debugfs.c
@@ -1117,6 +1117,11 @@ static ssize_t ath12k_debugfs_dump_device_dp_stats(struct file *file,
 		len += scnprintf(buf + len, size - len, "ring%d: %u\n",
 				 i, device_stats->tx_err.desc_na[i]);
 
+	len += scnprintf(buf + len, size - len, "\nTX Descriptor Pool Alloc Failures:\n");
+	for (i = 0; i < ATH12K_HW_MAX_QUEUES; i++)
+		len += scnprintf(buf + len, size - len, "pool%d: %u\n",
+				 i, device_stats->tx_err.txbuf_na[i]);
+
 	len += scnprintf(buf + len, size - len,
 			 "\nMisc Transmit Failures: %d\n",
 			 atomic_read(&device_stats->tx_err.misc_fail));
diff --git a/drivers/net/wireless/ath/ath12k/dp.h b/drivers/net/wireless/ath/ath12k/dp.h
index bef0f2ba0560..16675210806a 100644
--- a/drivers/net/wireless/ath/ath12k/dp.h
+++ b/drivers/net/wireless/ath/ath12k/dp.h
@@ -429,6 +429,8 @@ struct ath12k_dp_arch_ops {
 struct ath12k_device_dp_tx_err_stats {
 	/* TCL Ring Descriptor unavailable */
 	u32 desc_na[DP_TCL_NUM_RING_MAX];
+	/* TX descriptor pool exhausted (per pool_id / traffic class) */
+	u32 txbuf_na[ATH12K_HW_MAX_QUEUES];
 	/* Other failures during dp_tx due to mem allocation failure
 	 * idr unavailable etc.
 	 */
diff --git a/drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c b/drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c
index d46a3d14f018..f572aa581d11 100644
--- a/drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c
+++ b/drivers/net/wireless/ath/ath12k/wifi7/dp_tx.c
@@ -167,8 +167,10 @@ int ath12k_wifi7_dp_tx(struct ath12k_pdev_dp *dp_pdev, struct ath12k_link_vif *a
 	tx_ring = &dp->tx_ring[ti.ring_id];
 
 	tx_desc = ath12k_dp_tx_assign_buffer(dp, pool_id);
-	if (!tx_desc)
+	if (!tx_desc) {
+		dp->device_stats.tx_err.txbuf_na[pool_id]++;
 		return -ENOMEM;
+	}
 
 	dp_link_vif = ath12k_dp_vif_to_dp_link_vif(&ahvif->dp_vif, arvif->link_id);
 
-- 
2.34.1