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Message-ID: <be2cd114-38c6-d539-446a-a35a872449fc@gmail.com>
Date:   Tue, 18 Apr 2023 16:04:31 +0300
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To:     "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
Cc:     Jes Sorensen <Jes.Sorensen@gmail.com>,
        Ping-Ke Shih <pkshih@realtek.com>
From:   Bitterblue Smith <rtl8821cerfe2@gmail.com>
Subject: [PATCH] wifi: rtl8xxxu: Support USB RX aggregation for the newer
 chips
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The driver can receive several frames in the same USB transfer.
Add the code to handle this in rtl8xxxu_parse_rxdesc24(), even though
currently all the relevant chips send only one frame per USB transfer
(RTL8723BU, RTL8192EU, RTL8188FU, RTL8710BU).

rtl8xxxu_parse_rxdesc16() used by RTL8723AU, RTL8192CU, and RTL8188EU
already handles RX aggregation.

This was tested with RTL8188FU, RTL8192EU, RTL8710BU, and RTL8192FU.

Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
---
 .../wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 117 ++++++++++++------
 1 file changed, 76 insertions(+), 41 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
index fd8c8c6d53d6..5fccd898d607 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -6197,61 +6197,96 @@ int rtl8xxxu_parse_rxdesc16(struct rtl8xxxu_priv *priv, struct sk_buff *skb)
 int rtl8xxxu_parse_rxdesc24(struct rtl8xxxu_priv *priv, struct sk_buff *skb)
 {
 	struct ieee80211_hw *hw = priv->hw;
-	struct ieee80211_rx_status *rx_status = IEEE80211_SKB_RXCB(skb);
-	struct rtl8xxxu_rxdesc24 *rx_desc =
-		(struct rtl8xxxu_rxdesc24 *)skb->data;
+	struct ieee80211_rx_status *rx_status;
+	struct rtl8xxxu_rxdesc24 *rx_desc;
 	struct rtl8723au_phy_stats *phy_stats;
-	__le32 *_rx_desc_le = (__le32 *)skb->data;
-	u32 *_rx_desc = (u32 *)skb->data;
+	struct sk_buff *next_skb = NULL;
+	__le32 *_rx_desc_le;
+	u32 *_rx_desc;
 	int drvinfo_sz, desc_shift;
-	int i;
+	int i, pkt_len, urb_len, pkt_offset;
 
-	for (i = 0; i < (sizeof(struct rtl8xxxu_rxdesc24) / sizeof(u32)); i++)
-		_rx_desc[i] = le32_to_cpu(_rx_desc_le[i]);
+	urb_len = skb->len;
 
-	memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
+	if (urb_len < sizeof(struct rtl8xxxu_rxdesc24)) {
+		kfree_skb(skb);
+		return RX_TYPE_ERROR;
+	}
 
-	skb_pull(skb, sizeof(struct rtl8xxxu_rxdesc24));
+	do {
+		rx_desc = (struct rtl8xxxu_rxdesc24 *)skb->data;
+		_rx_desc_le = (__le32 *)skb->data;
+		_rx_desc = (u32 *)skb->data;
 
-	phy_stats = (struct rtl8723au_phy_stats *)skb->data;
+		for (i = 0; i < (sizeof(struct rtl8xxxu_rxdesc24) / sizeof(u32)); i++)
+			_rx_desc[i] = le32_to_cpu(_rx_desc_le[i]);
 
-	drvinfo_sz = rx_desc->drvinfo_sz * 8;
-	desc_shift = rx_desc->shift;
-	skb_pull(skb, drvinfo_sz + desc_shift);
+		pkt_len = rx_desc->pktlen;
 
-	if (rx_desc->rpt_sel) {
-		struct device *dev = &priv->udev->dev;
-		dev_dbg(dev, "%s: C2H packet\n", __func__);
-		rtl8723bu_handle_c2h(priv, skb);
-		return RX_TYPE_C2H;
-	}
+		drvinfo_sz = rx_desc->drvinfo_sz * 8;
+		desc_shift = rx_desc->shift;
+		pkt_offset = roundup(pkt_len + drvinfo_sz + desc_shift +
+				     sizeof(struct rtl8xxxu_rxdesc24), 8);
 
-	if (rx_desc->phy_stats)
-		priv->fops->parse_phystats(priv, rx_status, phy_stats,
-					   rx_desc->rxmcs, (struct ieee80211_hdr *)skb->data,
-					   rx_desc->crc32 || rx_desc->icverr);
+		/*
+		 * Only clone the skb if there's enough data at the end to
+		 * at least cover the rx descriptor
+		 */
+		if (urb_len >= (pkt_offset + sizeof(struct rtl8xxxu_rxdesc24)))
+			next_skb = skb_clone(skb, GFP_ATOMIC);
 
-	rx_status->mactime = rx_desc->tsfl;
-	rx_status->flag |= RX_FLAG_MACTIME_START;
+		rx_status = IEEE80211_SKB_RXCB(skb);
+		memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
 
-	if (!rx_desc->swdec)
-		rx_status->flag |= RX_FLAG_DECRYPTED;
-	if (rx_desc->crc32)
-		rx_status->flag |= RX_FLAG_FAILED_FCS_CRC;
-	if (rx_desc->bw)
-		rx_status->bw = RATE_INFO_BW_40;
+		skb_pull(skb, sizeof(struct rtl8xxxu_rxdesc24));
 
-	if (rx_desc->rxmcs >= DESC_RATE_MCS0) {
-		rx_status->encoding = RX_ENC_HT;
-		rx_status->rate_idx = rx_desc->rxmcs - DESC_RATE_MCS0;
-	} else {
-		rx_status->rate_idx = rx_desc->rxmcs;
-	}
+		phy_stats = (struct rtl8723au_phy_stats *)skb->data;
+
+		skb_pull(skb, drvinfo_sz + desc_shift);
+
+		skb_trim(skb, pkt_len);
+
+		if (rx_desc->rpt_sel) {
+			struct device *dev = &priv->udev->dev;
+			dev_dbg(dev, "%s: C2H packet\n", __func__);
+			rtl8723bu_handle_c2h(priv, skb);
+		} else {
+			if (rx_desc->phy_stats)
+				priv->fops->parse_phystats(priv, rx_status, phy_stats,
+							   rx_desc->rxmcs, (struct ieee80211_hdr *)skb->data,
+							   rx_desc->crc32 || rx_desc->icverr);
+
+			rx_status->mactime = rx_desc->tsfl;
+			rx_status->flag |= RX_FLAG_MACTIME_START;
+
+			if (!rx_desc->swdec)
+				rx_status->flag |= RX_FLAG_DECRYPTED;
+			if (rx_desc->crc32)
+				rx_status->flag |= RX_FLAG_FAILED_FCS_CRC;
+			if (rx_desc->bw)
+				rx_status->bw = RATE_INFO_BW_40;
 
-	rx_status->freq = hw->conf.chandef.chan->center_freq;
-	rx_status->band = hw->conf.chandef.chan->band;
+			if (rx_desc->rxmcs >= DESC_RATE_MCS0) {
+				rx_status->encoding = RX_ENC_HT;
+				rx_status->rate_idx = rx_desc->rxmcs - DESC_RATE_MCS0;
+			} else {
+				rx_status->rate_idx = rx_desc->rxmcs;
+			}
+
+			rx_status->freq = hw->conf.chandef.chan->center_freq;
+			rx_status->band = hw->conf.chandef.chan->band;
+
+			ieee80211_rx_irqsafe(hw, skb);
+		}
+
+		skb = next_skb;
+		if (skb)
+			skb_pull(next_skb, pkt_offset);
+
+		urb_len -= pkt_offset;
+		next_skb = NULL;
+	} while (skb && urb_len >= sizeof(struct rtl8xxxu_rxdesc24));
 
-	ieee80211_rx_irqsafe(hw, skb);
 	return RX_TYPE_DATA_PKT;
 }
 
-- 
2.39.2