[v4,3/4] wifi: rtw88: usb: Support RX aggregation

Commit Message

Bitterblue Smith Aug. 7, 2024, 10:21 p.m. UTC

The chips can be configured to aggregate several frames into a single
USB transfer. Modify rtw_usb_rx_handler() to support this case.

RX aggregation improves the RX speed of RTL8811CU on certain ARM
systems, like the NanoPi NEO Core2. It also improves the RX speed of
RTL8822CU on some x86_64 systems.

Currently none of the chips are configured to aggregate frames.

Tested with RTL8822CU, RTL8811CU, and RTL8723DU.

Reviewed-by: Sascha Hauer <[e-mail]>
Tested-by: Sascha Hauer <[e-mail]>
Signed-off-by: Bitterblue Smith <[e-mail]>
---
v4:
 - Mention testing with RTL8822CU and the effect on it.

v3:
 - Don't initialise next_skb.
 - Add Tested-by and Reviewed-by: Sascha Hauer <[e-mail]>

v2:
 - Simplify the code and make it more readable.
 - Rebase on top of latest rtw-next.
---
 drivers/net/wireless/realtek/rtw88/usb.c | 61 ++++++++++++++++--------
 1 file changed, 40 insertions(+), 21 deletions(-)

Patch

diff --git a/drivers/net/wireless/realtek/rtw88/usb.c b/drivers/net/wireless/realtek/rtw88/usb.c
index 10f1d724370e..64d68366812c 100644
--- a/drivers/net/wireless/realtek/rtw88/usb.c
+++ b/drivers/net/wireless/realtek/rtw88/usb.c
@@ -546,11 +546,12 @@  static void rtw_usb_rx_handler(struct work_struct *work)
 	struct rtw_usb *rtwusb = container_of(work, struct rtw_usb, rx_work);
 	struct rtw_dev *rtwdev = rtwusb->rtwdev;
 	const struct rtw_chip_info *chip = rtwdev->chip;
-	struct rtw_rx_pkt_stat pkt_stat;
+	u32 pkt_desc_sz = chip->rx_pkt_desc_sz;
 	struct ieee80211_rx_status rx_status;
+	u32 pkt_offset, next_pkt, urb_len;
+	struct rtw_rx_pkt_stat pkt_stat;
+	struct sk_buff *next_skb;
 	struct sk_buff *skb;
-	u32 pkt_desc_sz = chip->rx_pkt_desc_sz;
-	u32 pkt_offset;
 	u8 *rx_desc;
 	int limit;
 
@@ -559,31 +560,48 @@  static void rtw_usb_rx_handler(struct work_struct *work)
 		if (!skb)
 			break;
 
-		rx_desc = skb->data;
-		chip->ops->query_rx_desc(rtwdev, rx_desc, &pkt_stat,
-					 &rx_status);
-		pkt_offset = pkt_desc_sz + pkt_stat.drv_info_sz +
-			     pkt_stat.shift;
-
-		if (pkt_stat.is_c2h) {
-			skb_put(skb, pkt_stat.pkt_len + pkt_offset);
-			rtw_fw_c2h_cmd_rx_irqsafe(rtwdev, pkt_offset, skb);
-			continue;
-		}
-
 		if (skb_queue_len(&rtwusb->rx_queue) >= RTW_USB_MAX_RXQ_LEN) {
 			dev_dbg_ratelimited(rtwdev->dev, "failed to get rx_queue, overflow\n");
 			dev_kfree_skb_any(skb);
 			continue;
 		}
 
-		skb_put(skb, pkt_stat.pkt_len);
-		skb_reserve(skb, pkt_offset);
+		urb_len = skb->len;
+
+		do {
+			rx_desc = skb->data;
+			chip->ops->query_rx_desc(rtwdev, rx_desc, &pkt_stat,
+						 &rx_status);
+			pkt_offset = pkt_desc_sz + pkt_stat.drv_info_sz +
+				     pkt_stat.shift;
+
+			next_pkt = round_up(pkt_stat.pkt_len + pkt_offset, 8);
+
+			if (urb_len >= next_pkt + pkt_desc_sz)
+				next_skb = skb_clone(skb, GFP_KERNEL);
+			else
+				next_skb = NULL;
+
+			if (pkt_stat.is_c2h) {
+				skb_trim(skb, pkt_stat.pkt_len + pkt_offset);
+				rtw_fw_c2h_cmd_rx_irqsafe(rtwdev, pkt_offset, skb);
+			} else {
+				skb_pull(skb, pkt_offset);
+				skb_trim(skb, pkt_stat.pkt_len);
+				rtw_update_rx_freq_for_invalid(rtwdev, skb,
+							       &rx_status,
+							       &pkt_stat);
+				rtw_rx_stats(rtwdev, pkt_stat.vif, skb);
+				memcpy(skb->cb, &rx_status, sizeof(rx_status));
+				ieee80211_rx_irqsafe(rtwdev->hw, skb);
+			}
+
+			skb = next_skb;
+			if (skb)
+				skb_pull(skb, next_pkt);
 
-		rtw_update_rx_freq_for_invalid(rtwdev, skb, &rx_status, &pkt_stat);
-		rtw_rx_stats(rtwdev, pkt_stat.vif, skb);
-		memcpy(skb->cb, &rx_status, sizeof(rx_status));
-		ieee80211_rx_irqsafe(rtwdev->hw, skb);
+			urb_len -= next_pkt;
+		} while (skb);
 	}
 }
 
@@ -627,6 +645,7 @@  static void rtw_usb_read_port_complete(struct urb *urb)
 			if (skb)
 				dev_kfree_skb_any(skb);
 		} else {
+			skb_put(skb, urb->actual_length);
 			skb_queue_tail(&rtwusb->rx_queue, skb);
 			queue_work(rtwusb->rxwq, &rtwusb->rx_work);
 		}