rt2x00: Fix rt2800usb RX frame format and as such L2PAD

According to Ralink source code, the RX frame format is RXINFO + RXWI +
802.11 frame + RXD, including various padding. Before this patch, we
were using RXD + RXWI + 802.11 frame, so RXD was not correct.

Doing this, we fix the L2PAD bit which is now correctly set on received
frames.
Signed-off-by: Benoit Papillault <benoit.papillault@free.fr>
Acked-by: Ivo van Doorn <ivdoorn@gmail.com>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2800usb.c

@@ -571,41 +571,57 @@ static void rt2800usb_fill_rxdone(struct queue_entry *entry,
 {
 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 	struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
-	__le32 *rxd = (__le32 *)entry->skb->data;
+	__le32 *rxi = (__le32 *)entry->skb->data;
 	__le32 *rxwi;
-	u32 rxd0;
+	__le32 *rxd;
+	u32 rxi0;
 	u32 rxwi0;
 	u32 rxwi1;
 	u32 rxwi2;
 	u32 rxwi3;
+	u32 rxd0;
+	int rx_pkt_len;
+
+	/*
+	 * RX frame format is :
+	 * | RXINFO | RXWI | header | L2 pad | payload | pad | RXD | USB pad |
+	 *          |<------------ rx_pkt_len -------------->|
+	 */
+	rt2x00_desc_read(rxi, 0, &rxi0);
+	rx_pkt_len = rt2x00_get_field32(rxi0, RXINFO_W0_USB_DMA_RX_PKT_LEN);
+
+	rxwi = (__le32 *)(entry->skb->data + RXINFO_DESC_SIZE);
+
+	/*
+	 * FIXME : we need to check for rx_pkt_len validity
+	 */
+	rxd = (__le32 *)(entry->skb->data + RXINFO_DESC_SIZE + rx_pkt_len);
 
 	/*
 	 * Copy descriptor to the skbdesc->desc buffer, making it safe from
 	 * moving of frame data in rt2x00usb.
 	 */
-	memcpy(skbdesc->desc, rxd, skbdesc->desc_len);
-	rxd = (__le32 *)skbdesc->desc;
-	rxwi = &rxd[RXINFO_DESC_SIZE / sizeof(__le32)];
+	memcpy(skbdesc->desc, rxi, skbdesc->desc_len);
 
 	/*
 	 * It is now safe to read the descriptor on all architectures.
 	 */
-	rt2x00_desc_read(rxd, 0, &rxd0);
 	rt2x00_desc_read(rxwi, 0, &rxwi0);
 	rt2x00_desc_read(rxwi, 1, &rxwi1);
 	rt2x00_desc_read(rxwi, 2, &rxwi2);
 	rt2x00_desc_read(rxwi, 3, &rxwi3);
+	rt2x00_desc_read(rxd, 0, &rxd0);
 
-	if (rt2x00_get_field32(rxd0, RXINFO_W0_CRC_ERROR))
+	if (rt2x00_get_field32(rxd0, RXD_W0_CRC_ERROR))
 		rxdesc->flags |= RX_FLAG_FAILED_FCS_CRC;
 
 	if (test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags)) {
 		rxdesc->cipher = rt2x00_get_field32(rxwi0, RXWI_W0_UDF);
 		rxdesc->cipher_status =
-		    rt2x00_get_field32(rxd0, RXINFO_W0_CIPHER_ERROR);
+		    rt2x00_get_field32(rxd0, RXD_W0_CIPHER_ERROR);
 	}
 
-	if (rt2x00_get_field32(rxd0, RXINFO_W0_DECRYPTED)) {
+	if (rt2x00_get_field32(rxd0, RXD_W0_DECRYPTED)) {
 		/*
 		 * Hardware has stripped IV/EIV data from 802.11 frame during
 		 * decryption. Unfortunately the descriptor doesn't contain
@@ -620,10 +636,10 @@ static void rt2800usb_fill_rxdone(struct queue_entry *entry,
 			rxdesc->flags |= RX_FLAG_MMIC_ERROR;
 	}
 
-	if (rt2x00_get_field32(rxd0, RXINFO_W0_MY_BSS))
+	if (rt2x00_get_field32(rxd0, RXD_W0_MY_BSS))
 		rxdesc->dev_flags |= RXDONE_MY_BSS;
 
-	if (rt2x00_get_field32(rxd0, RXINFO_W0_L2PAD))
+	if (rt2x00_get_field32(rxd0, RXD_W0_L2PAD))
 		rxdesc->dev_flags |= RXDONE_L2PAD;
 
 	if (rt2x00_get_field32(rxwi1, RXWI_W1_SHORT_GI))

drivers/net/wireless/rt2x00/rt2800usb.h

@@ -79,6 +79,8 @@
  */
 #define TXINFO_DESC_SIZE		( 1 * sizeof(__le32) )
 #define RXINFO_DESC_SIZE		( 1 * sizeof(__le32) )
+#define RXWI_DESC_SIZE			( 4 * sizeof(__le32) )
+#define RXD_DESC_SIZE			( 1 * sizeof(__le32) )
 
 /*
  * TX Info structure
@@ -100,6 +102,54 @@
 #define TXINFO_W0_USB_DMA_NEXT_VALID	FIELD32(0x40000000)
 #define TXINFO_W0_USB_DMA_TX_BURST	FIELD32(0x80000000)
 
+/*
+ * RX Info structure
+ */
+
+/*
+ * Word 0
+ */
+
+#define RXINFO_W0_USB_DMA_RX_PKT_LEN	FIELD32(0x0000ffff)
+
+/*
+ * RX WI structure
+ */
+
+/*
+ * Word0
+ */
+#define RXWI_W0_WIRELESS_CLI_ID		FIELD32(0x000000ff)
+#define RXWI_W0_KEY_INDEX		FIELD32(0x00000300)
+#define RXWI_W0_BSSID			FIELD32(0x00001c00)
+#define RXWI_W0_UDF			FIELD32(0x0000e000)
+#define RXWI_W0_MPDU_TOTAL_BYTE_COUNT	FIELD32(0x0fff0000)
+#define RXWI_W0_TID			FIELD32(0xf0000000)
+
+/*
+ * Word1
+ */
+#define RXWI_W1_FRAG			FIELD32(0x0000000f)
+#define RXWI_W1_SEQUENCE		FIELD32(0x0000fff0)
+#define RXWI_W1_MCS			FIELD32(0x007f0000)
+#define RXWI_W1_BW			FIELD32(0x00800000)
+#define RXWI_W1_SHORT_GI		FIELD32(0x01000000)
+#define RXWI_W1_STBC			FIELD32(0x06000000)
+#define RXWI_W1_PHYMODE			FIELD32(0xc0000000)
+
+/*
+ * Word2
+ */
+#define RXWI_W2_RSSI0			FIELD32(0x000000ff)
+#define RXWI_W2_RSSI1			FIELD32(0x0000ff00)
+#define RXWI_W2_RSSI2			FIELD32(0x00ff0000)
+
+/*
+ * Word3
+ */
+#define RXWI_W3_SNR0			FIELD32(0x000000ff)
+#define RXWI_W3_SNR1			FIELD32(0x0000ff00)
+
 /*
  * RX descriptor format for RX Ring.
  */
@@ -115,25 +165,25 @@
  * AMSDU: rx with 802.3 header, not 802.11 header.
  */
 
-#define RXINFO_W0_BA			FIELD32(0x00000001)
-#define RXINFO_W0_DATA			FIELD32(0x00000002)
-#define RXINFO_W0_NULLDATA		FIELD32(0x00000004)
-#define RXINFO_W0_FRAG			FIELD32(0x00000008)
-#define RXINFO_W0_UNICAST_TO_ME		FIELD32(0x00000010)
-#define RXINFO_W0_MULTICAST		FIELD32(0x00000020)
-#define RXINFO_W0_BROADCAST		FIELD32(0x00000040)
-#define RXINFO_W0_MY_BSS		FIELD32(0x00000080)
-#define RXINFO_W0_CRC_ERROR		FIELD32(0x00000100)
-#define RXINFO_W0_CIPHER_ERROR		FIELD32(0x00000600)
-#define RXINFO_W0_AMSDU			FIELD32(0x00000800)
-#define RXINFO_W0_HTC			FIELD32(0x00001000)
-#define RXINFO_W0_RSSI			FIELD32(0x00002000)
-#define RXINFO_W0_L2PAD			FIELD32(0x00004000)
-#define RXINFO_W0_AMPDU			FIELD32(0x00008000)
-#define RXINFO_W0_DECRYPTED		FIELD32(0x00010000)
-#define RXINFO_W0_PLCP_RSSI		FIELD32(0x00020000)
-#define RXINFO_W0_CIPHER_ALG		FIELD32(0x00040000)
-#define RXINFO_W0_LAST_AMSDU		FIELD32(0x00080000)
-#define RXINFO_W0_PLCP_SIGNAL		FIELD32(0xfff00000)
+#define RXD_W0_BA			FIELD32(0x00000001)
+#define RXD_W0_DATA			FIELD32(0x00000002)
+#define RXD_W0_NULLDATA			FIELD32(0x00000004)
+#define RXD_W0_FRAG			FIELD32(0x00000008)
+#define RXD_W0_UNICAST_TO_ME		FIELD32(0x00000010)
+#define RXD_W0_MULTICAST		FIELD32(0x00000020)
+#define RXD_W0_BROADCAST		FIELD32(0x00000040)
+#define RXD_W0_MY_BSS			FIELD32(0x00000080)
+#define RXD_W0_CRC_ERROR		FIELD32(0x00000100)
+#define RXD_W0_CIPHER_ERROR		FIELD32(0x00000600)
+#define RXD_W0_AMSDU			FIELD32(0x00000800)
+#define RXD_W0_HTC			FIELD32(0x00001000)
+#define RXD_W0_RSSI			FIELD32(0x00002000)
+#define RXD_W0_L2PAD			FIELD32(0x00004000)
+#define RXD_W0_AMPDU			FIELD32(0x00008000)
+#define RXD_W0_DECRYPTED		FIELD32(0x00010000)
+#define RXD_W0_PLCP_RSSI		FIELD32(0x00020000)
+#define RXD_W0_CIPHER_ALG		FIELD32(0x00040000)
+#define RXD_W0_LAST_AMSDU		FIELD32(0x00080000)
+#define RXD_W0_PLCP_SIGNAL		FIELD32(0xfff00000)
 
 #endif /* RT2800USB_H */