[PATCH v2] wifi: rtl8xxxu: Support USB RX aggregation for the newer chips

[PATCH v2] wifi: rtl8xxxu: Support USB RX aggregation for the newer chips

[Bitterblue Smith]

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).

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

Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
---
v2:
 - Suggestion by Ping-Ke Shih:
   - Add variable hdr to make a long line shorter.
 - Don't say rtl8xxxu_parse_rxdesc16() already handles RX aggregation.
   That function needs more work.
---
 .../wireless/realtek/rtl8xxxu/rtl8xxxu_core.c | 119 ++++++++++++------
 1 file changed, 78 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..1ce18dc8a41e 100644
--- a/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
+++ b/drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c
@@ -6197,61 +6197,98 @@ 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);
+
+		/*
+		 * 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);
 
-	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 = IEEE80211_SKB_RXCB(skb);
+		memset(rx_status, 0, sizeof(struct ieee80211_rx_status));
 
-	rx_status->mactime = rx_desc->tsfl;
-	rx_status->flag |= RX_FLAG_MACTIME_START;
+		skb_pull(skb, sizeof(struct rtl8xxxu_rxdesc24));
 
-	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;
+		phy_stats = (struct rtl8723au_phy_stats *)skb->data;
 
-	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;
-	}
+		skb_pull(skb, drvinfo_sz + desc_shift);
 
-	rx_status->freq = hw->conf.chandef.chan->center_freq;
-	rx_status->band = hw->conf.chandef.chan->band;
+		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 {
+			struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
+
+			if (rx_desc->phy_stats)
+				priv->fops->parse_phystats(priv, rx_status, phy_stats,
+							   rx_desc->rxmcs, hdr,
+							   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;
+
+			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

RE: [PATCH v2] wifi: rtl8xxxu: Support USB RX aggregation for the newer chips

[Ping-Ke Shih]

> -----Original Message-----
> From: Bitterblue Smith <rtl8821cerfe2@gmail.com>
> Sent: Tuesday, April 25, 2023 9:01 PM
> To: linux-wireless@vger.kernel.org
> Cc: Jes Sorensen <Jes.Sorensen@gmail.com>; Ping-Ke Shih <pkshih@realtek.com>
> Subject: [PATCH v2] wifi: rtl8xxxu: Support USB RX aggregation for the newer chips
> 
> 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).
> 
> This was tested with RTL8188FU, RTL8192EU, RTL8710BU, and RTL8192FU.
> 
> Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>

Reviewed-by: Ping-Ke Shih <pkshih@realtek.com>

> ---
> v2:
>  - Suggestion by Ping-Ke Shih:
>    - Add variable hdr to make a long line shorter.
>  - Don't say rtl8xxxu_parse_rxdesc16() already handles RX aggregation.
>    That function needs more work.
> ---

[...]

Re: [PATCH v2] wifi: rtl8xxxu: Support USB RX aggregation for the newer chips

[Kalle Valo]

Bitterblue Smith <rtl8821cerfe2@gmail.com> wrote:

> 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).
> 
> This was tested with RTL8188FU, RTL8192EU, RTL8710BU, and RTL8192FU.
> 
> Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
> Reviewed-by: Ping-Ke Shih <pkshih@realtek.com>

Patch applied to wireless-next.git, thanks.

6dc28456aa17 wifi: rtl8xxxu: Support USB RX aggregation for the newer chips

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/16d2d1ff-6438-10c9-347f-6e14dd358ccf@gmail.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches