wifi: ath12k: Set congestion control max MSDU count

Currently when running 128 clients UDP DL test in 5 GHz HE80 (NSS 2x2),
firmware uses the default max MSDU count (16K MSDUs). This lower limit
causes the firmware to compute a smaller TQM drop threshold, aggregate
packets at a reduced rate, and results in increased packet drops with
TQM drop threshold as the completion reason.

To fix this issue, set WMI_PDEV_PARAM_SET_CONG_CTRL_MAX_MSDUS to the TX
descriptor count using ath12k_wmi_pdev_set_param(). This increases the
TQM drop threshold, reduces drop events, and improves throughput from
~722 Mbps to ~1060 Mbps with 1200 Mbps ingress.

Add a new HW capability flag (supports_cong_ctrl_max_msdus) and enable
the WMI parameter only on supported platforms.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.6-01181-QCAHKSWPL_SILICONZ-1

Signed-off-by: Thiraviyam Mariyappan <thiraviyam.mariyappan@oss.qualcomm.com>
Reviewed-by: Baochen Qiang <baochen.qiang@oss.qualcomm.com>
Reviewed-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>
Link: https://patch.msgid.link/20260622062614.760166-1-thiraviyam.mariyappan@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>

4 files changed, 21 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath12k/hw.h b/drivers/net/wireless/ath/ath12k/hw.h
index d135b2936378..ad62f93441b3 100644
--- a/drivers/net/wireless/ath/ath12k/hw.h
+++ b/drivers/net/wireless/ath/ath12k/hw.h
@@ -192,6 +192,7 @@ struct ath12k_hw_params {
 	bool supports_shadow_regs:1;
 	bool supports_aspm:1;
 	bool current_cc_support:1;
+	bool supports_cong_ctrl_max_msdus:1;
 
 	u32 num_tcl_banks;
 	u32 max_tx_ring;
diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
index d7e93a20ca36..5e4798ae8e99 100644
--- a/drivers/net/wireless/ath/ath12k/mac.c
+++ b/drivers/net/wireless/ath/ath12k/mac.c
@@ -9722,6 +9722,19 @@ static int ath12k_mac_start(struct ath12k *ar)
 		goto err;
 	}
 
+	if (ab->hw_params->supports_cong_ctrl_max_msdus) {
+		ret = ath12k_wmi_pdev_set_param(ar,
+						WMI_PDEV_PARAM_SET_CONG_CTRL_MAX_MSDUS,
+						ATH12K_NUM_POOL_TX_DESC(ab),
+						pdev->pdev_id);
+		if (ret) {
+			ath12k_err(ab,
+				   "failed to set congestion control MAX MSDUS: %d\n",
+				   ret);
+			goto err;
+		}
+	}
+
 	__ath12k_set_antenna(ar, ar->cfg_tx_chainmask, ar->cfg_rx_chainmask);
 
 	/* TODO: Do we need to enable ANI? */
diff --git a/drivers/net/wireless/ath/ath12k/wifi7/hw.c b/drivers/net/wireless/ath/ath12k/wifi7/hw.c
index 8bc841dbac00..1ab1168510aa 100644
--- a/drivers/net/wireless/ath/ath12k/wifi7/hw.c
+++ b/drivers/net/wireless/ath/ath12k/wifi7/hw.c
@@ -390,6 +390,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
 					BIT(NL80211_IFTYPE_MESH_POINT) |
 					BIT(NL80211_IFTYPE_AP_VLAN),
 		.supports_monitor = false,
+		.supports_cong_ctrl_max_msdus = true,
 
 		.idle_ps = false,
 		.download_calib = true,
@@ -480,6 +481,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
 				   BIT(NL80211_IFTYPE_P2P_CLIENT) |
 				   BIT(NL80211_IFTYPE_P2P_GO),
 		.supports_monitor = true,
+		.supports_cong_ctrl_max_msdus = false,
 
 		.idle_ps = true,
 		.download_calib = false,
@@ -568,6 +570,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
 					BIT(NL80211_IFTYPE_MESH_POINT) |
 					BIT(NL80211_IFTYPE_AP_VLAN),
 		.supports_monitor = true,
+		.supports_cong_ctrl_max_msdus = true,
 
 		.idle_ps = false,
 		.download_calib = true,
@@ -654,6 +657,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
 				   BIT(NL80211_IFTYPE_AP) |
 				   BIT(NL80211_IFTYPE_MESH_POINT),
 		.supports_monitor = true,
+		.supports_cong_ctrl_max_msdus = true,
 
 		.idle_ps = false,
 		.download_calib = true,
@@ -738,6 +742,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
 				   BIT(NL80211_IFTYPE_P2P_CLIENT) |
 				   BIT(NL80211_IFTYPE_P2P_GO),
 		.supports_monitor = true,
+		.supports_cong_ctrl_max_msdus = false,
 
 		.idle_ps = true,
 		.download_calib = false,
@@ -826,6 +831,7 @@ static const struct ath12k_hw_params ath12k_wifi7_hw_params[] = {
 				   BIT(NL80211_IFTYPE_AP) |
 				   BIT(NL80211_IFTYPE_MESH_POINT),
 		.supports_monitor = true,
+		.supports_cong_ctrl_max_msdus = true,
 
 		.idle_ps = false,
 		.download_calib = true,
diff --git a/drivers/net/wireless/ath/ath12k/wmi.h b/drivers/net/wireless/ath/ath12k/wmi.h
index 20e3939e8820..c813b2848b5b 100644
--- a/drivers/net/wireless/ath/ath12k/wmi.h
+++ b/drivers/net/wireless/ath/ath12k/wmi.h
@@ -1083,6 +1083,7 @@ enum wmi_tlv_pdev_param {
 	WMI_PDEV_PARAM_RADIO_CHAN_STATS_ENABLE,
 	WMI_PDEV_PARAM_RADIO_DIAGNOSIS_ENABLE,
 	WMI_PDEV_PARAM_MESH_MCAST_ENABLE,
+	WMI_PDEV_PARAM_SET_CONG_CTRL_MAX_MSDUS = 0xa6,
 	WMI_PDEV_PARAM_SET_CMD_OBSS_PD_THRESHOLD = 0xbc,
 	WMI_PDEV_PARAM_SET_CMD_OBSS_PD_PER_AC = 0xbe,
 	WMI_PDEV_PARAM_ENABLE_SR_PROHIBIT = 0xc6,