mt76: mt7915: disable RED support in the WA firmware

It causes high CPU load on the WA core, which can lead to extra latency when
using many stations. Dropping packets for long queues is managed by mac80211
fq_codel instead
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/mt7915/mcu.c

@@ -313,6 +313,22 @@ mt7915_mcu_send_message(struct mt76_dev *mdev, struct sk_buff *skb,
 	return mt76_tx_queue_skb_raw(dev, mdev->q_mcu[txq], skb, 0);
 }
 
+static void
+mt7915_mcu_wa_cmd(struct mt7915_dev *dev, int cmd, u32 a1, u32 a2, u32 a3)
+{
+	struct {
+		__le32 args[3];
+	} req = {
+		.args = {
+			cpu_to_le32(a1),
+			cpu_to_le32(a2),
+			cpu_to_le32(a3),
+		},
+	};
+
+	mt76_mcu_send_msg(&dev->mt76, cmd, &req, sizeof(req), true);
+}
+
 static void
 mt7915_mcu_csa_finish(void *priv, u8 *mac, struct ieee80211_vif *vif)
 {
@@ -2831,6 +2847,7 @@ int mt7915_mcu_init(struct mt7915_dev *dev)
 	set_bit(MT76_STATE_MCU_RUNNING, &dev->mphy.state);
 	mt7915_mcu_fw_log_2_host(dev, 0);
 	mt7915_mcu_set_mwds(dev, 1);
+	mt7915_mcu_wa_cmd(dev, MCU_WA_PARAM_CMD(SET), MCU_WA_PARAM_RED, 0, 0);
 
 	return 0;
 }

drivers/net/wireless/mediatek/mt76/mt7915/mcu.h

@@ -239,6 +239,7 @@ enum {
 	MCU_CMD_PATCH_START_REQ = 0x05,
 	MCU_CMD_PATCH_FINISH_REQ = 0x07,
 	MCU_CMD_PATCH_SEM_CONTROL = 0x10,
+	MCU_CMD_WA_PARAM = 0xC4,
 	MCU_CMD_EXT_CID = 0xED,
 	MCU_CMD_FW_SCATTER = 0xEE,
 	MCU_CMD_RESTART_DL_REQ = 0xEF,
@@ -277,6 +278,17 @@ enum {
 	MCU_EXT_CMD_PHY_STAT_INFO = 0xad,
 };
 
+enum {
+	MCU_WA_PARAM_CMD_QUERY,
+	MCU_WA_PARAM_CMD_SET,
+	MCU_WA_PARAM_CMD_CAPABILITY,
+	MCU_WA_PARAM_CMD_DEBUG,
+};
+
+enum {
+	MCU_WA_PARAM_RED = 0x0e,
+};
+
 #define MCU_CMD(_t)		FIELD_PREP(__MCU_CMD_FIELD_ID, MCU_CMD_##_t)
 #define MCU_EXT_CMD(_t)		(MCU_CMD(EXT_CID) | \
 				 FIELD_PREP(__MCU_CMD_FIELD_EXT_ID, \
@@ -285,6 +297,9 @@ enum {
 
 #define MCU_WA_CMD(_t)		(MCU_CMD(_t) | __MCU_CMD_FIELD_WA)
 #define MCU_WA_EXT_CMD(_t)	(MCU_EXT_CMD(_t) | __MCU_CMD_FIELD_WA)
+#define MCU_WA_PARAM_CMD(_t)	(MCU_WA_CMD(WA_PARAM) | \
+				 FIELD_PREP(__MCU_CMD_FIELD_EXT_ID, \
+					    MCU_WA_PARAM_CMD_##_t))
 
 enum {
 	PATCH_SEM_RELEASE,