[PATCH v2 net-next 4/6] qlcnic: fix estimation of receive MSS in case of LRO for 83xx adapter

[Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>]

From: Shahed Shaikh <shahed.shaikh@qlogic.com>

Set gso_size to MSS obtained from adapter to avoid incorrect estimation
of receive MSS, which would lead to delayed ACKs in some traffic patterns

Example:
Send two or three packets and wait for ack and only then send
remaining packets.

Signed-off-by: Shahed Shaikh <shahed.shaikh@qlogic.com>
Signed-off-by: Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>
---
 .../net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.h    |    1 +
 drivers/net/ethernet/qlogic/qlcnic/qlcnic_io.c     |   13 ++++++++++-
 drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c   |   24 +++++++++++++------
 3 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.h b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.h
index 127fa27..61f81f6 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.h
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.h
@@ -223,6 +223,7 @@ struct qlc_83xx_idc {
 #define QLC_83XX_GET_LSO_CAPABILITY(val)		(val & 0x40)
 #define QLC_83XX_GET_HW_LRO_CAPABILITY(val)		(val & 0x400)
 #define QLC_83XX_GET_VLAN_ALIGN_CAPABILITY(val)	(val & 0x4000)
+#define QLC_83XX_GET_FW_LRO_MSS_CAPABILITY(val)	(val & 0x20000)
 #define QLC_83XX_VIRTUAL_NIC_MODE			0xFF
 #define QLC_83XX_DEFAULT_MODE				0x0
 #define QLCNIC_BRDTYPE_83XX_10G			0x0083
diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_io.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_io.c
index 662292d..2990f45 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_io.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_io.c
@@ -88,6 +88,8 @@
 #define qlcnic_get_lro_sts_mss(sts_data1)		\
 	((sts_data1 >> 32) & 0x0FFFF)
 
+#define qlcnic_83xx_get_lro_sts_mss(sts) ((sts) & 0xffff)
+
 /* opcode field in status_desc */
 #define QLCNIC_SYN_OFFLOAD	0x03
 #define QLCNIC_RXPKT_DESC  	0x04
@@ -1423,7 +1425,7 @@ qlcnic_83xx_process_lro(struct qlcnic_adapter *adapter,
 	bool push;
 	int l2_hdr_offset, l4_hdr_offset;
 	int index;
-	u16 lro_length, length, data_offset;
+	u16 lro_length, length, data_offset, gso_size;
 	u16 vid = 0xffff;
 
 	if (unlikely(ring > adapter->max_rds_rings))
@@ -1478,6 +1480,15 @@ qlcnic_83xx_process_lro(struct qlcnic_adapter *adapter,
 	th->psh = push;
 	length = skb->len;
 
+	if (adapter->flags & QLCNIC_FW_LRO_MSS_CAP) {
+		gso_size = qlcnic_83xx_get_lro_sts_mss(sts_data[0]);
+		skb_shinfo(skb)->gso_size = gso_size;
+		if (skb->protocol == htons(ETH_P_IPV6))
+			skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
+		else
+			skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
+	}
+
 	if (vid != 0xffff)
 		__vlan_hwaccel_put_tag(skb, vid);
 
diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
index 3a0f182..e03017a 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c
@@ -1339,11 +1339,24 @@ qlcnic_free_irq(struct qlcnic_adapter *adapter)
 	}
 }
 
+static void qlcnic_get_lro_mss_capability(struct qlcnic_adapter *adapter)
+{
+	u32 capab = 0;
+
+	if (qlcnic_82xx_check(adapter)) {
+		if (adapter->ahw->capabilities2 &
+		    QLCNIC_FW_CAPABILITY_2_LRO_MAX_TCP_SEG)
+			adapter->flags |= QLCNIC_FW_LRO_MSS_CAP;
+	} else {
+		capab = adapter->ahw->capabilities;
+		if (QLC_83XX_GET_FW_LRO_MSS_CAPABILITY(capab))
+			adapter->flags |= QLCNIC_FW_LRO_MSS_CAP;
+	}
+}
+
 int __qlcnic_up(struct qlcnic_adapter *adapter, struct net_device *netdev)
 {
 	int ring;
-	u32 capab2;
-
 	struct qlcnic_host_rds_ring *rds_ring;
 
 	if (adapter->is_up != QLCNIC_ADAPTER_UP_MAGIC)
@@ -1353,12 +1366,7 @@ int __qlcnic_up(struct qlcnic_adapter *adapter, struct net_device *netdev)
 		return 0;
 	if (qlcnic_set_eswitch_port_config(adapter))
 		return -EIO;
-
-	if (adapter->ahw->capabilities & QLCNIC_FW_CAPABILITY_MORE_CAPS) {
-		capab2 = QLCRD32(adapter, CRB_FW_CAPABILITIES_2);
-		if (capab2 & QLCNIC_FW_CAPABILITY_2_LRO_MAX_TCP_SEG)
-			adapter->flags |= QLCNIC_FW_LRO_MSS_CAP;
-	}
+	qlcnic_get_lro_mss_capability(adapter);
 
 	if (qlcnic_fw_create_ctx(adapter))
 		return -EIO;
-- 
1.7.1