From: Mike Christie <mchristi@redhat.com>
Date: Thu, 18 Nov 2010 17:00:44 -0500
Subject: [net] cnic: Fine-tune ring init code
Message-id: <1290099647-9514-2-git-send-email-mchristi@redhat.com>
Patchwork-id: 29493
O-Subject: [RHEL 5.6 PATCH 1/4] cnic: Fine-tune ring init code.
Bugzilla: 651287
RH-Acked-by: David S. Miller <davem@redhat.com>

From: Mike Christie <mchristi@redhat.com>

This is for BZ 651287.

>From upstream commit:

commit 541a78103f097cd5120e55aaba56d099a64f153c
Author: Michael Chan <mchan@broadcom.com>
Date:   Wed Oct 6 03:17:22 2010 +0000

    cnic: Fine-tune ring init code.

    Initialize the rings only during cnic_uio_open() and shut them down
    during cnic_uio_close().  Check for the new bit CNIC_LCL_FL_RINGS_INITED
    before checking for ring interrupt.

diff --git a/drivers/net/cnic.c b/drivers/net/cnic.c
index 31a308e..f38c6b3 100644
--- a/drivers/net/cnic.c
+++ b/drivers/net/cnic.c
@@ -2187,10 +2187,14 @@ static int cnic_l2_completion(struct cnic_local *cp)
 
 static void cnic_chk_pkt_rings(struct cnic_local *cp)
 {
-	u16 rx_cons = *cp->rx_cons_ptr;
-	u16 tx_cons = *cp->tx_cons_ptr;
+	u16 rx_cons, tx_cons;
 	int comp = 0;
 
+	if (!test_bit(CNIC_LCL_FL_RINGS_INITED, &cp->cnic_local_flags))
+		return;
+
+	rx_cons = *cp->rx_cons_ptr;
+	tx_cons = *cp->tx_cons_ptr;
 	if (cp->tx_cons != tx_cons || cp->rx_cons != rx_cons) {
 		if (test_bit(CNIC_LCL_FL_L2_WAIT, &cp->cnic_local_flags))
 			comp = cnic_l2_completion(cp);
@@ -4243,17 +4247,20 @@ static int cnic_start_bnx2x_hw(struct cnic_dev *dev)
 	if (ret)
 		return ret;
 
-	cnic_init_bnx2x_tx_ring(dev);
-	cnic_init_bnx2x_rx_ring(dev);
-
 	return 0;
 }
 
 static void cnic_init_rings(struct cnic_dev *dev)
 {
+	struct cnic_local *cp = dev->cnic_priv;
+
+	if (test_bit(CNIC_LCL_FL_RINGS_INITED, &cp->cnic_local_flags))
+		return;
+
 	if (test_bit(CNIC_F_BNX2_CLASS, &dev->flags)) {
 		cnic_init_bnx2_tx_ring(dev);
 		cnic_init_bnx2_rx_ring(dev);
+		set_bit(CNIC_LCL_FL_RINGS_INITED, &cp->cnic_local_flags);
 	} else if (test_bit(CNIC_F_BNX2X_CLASS, &dev->flags)) {
 		struct cnic_local *cp = dev->cnic_priv;
 		u32 cli = BNX2X_ISCSI_CL_ID(CNIC_E1HVN(cp));
@@ -4276,6 +4283,8 @@ static void cnic_init_rings(struct cnic_dev *dev)
 		cnic_init_bnx2x_tx_ring(dev);
 		cnic_init_bnx2x_rx_ring(dev);
 
+		set_bit(CNIC_LCL_FL_RINGS_INITED, &cp->cnic_local_flags);
+
 		l5_data.phy_address.lo = cli;
 		l5_data.phy_address.hi = 0;
 		cnic_submit_kwqe_16(dev, RAMROD_CMD_ID_ETH_CLIENT_SETUP,
@@ -4296,6 +4305,11 @@ static void cnic_init_rings(struct cnic_dev *dev)
 
 static void cnic_shutdown_rings(struct cnic_dev *dev)
 {
+	struct cnic_local *cp = dev->cnic_priv;
+
+	if (!test_bit(CNIC_LCL_FL_RINGS_INITED, &cp->cnic_local_flags))
+		return;
+
 	if (test_bit(CNIC_F_BNX2_CLASS, &dev->flags)) {
 		cnic_shutdown_bnx2_rx_ring(dev);
 	} else if (test_bit(CNIC_F_BNX2X_CLASS, &dev->flags)) {
@@ -4329,6 +4343,7 @@ static void cnic_shutdown_rings(struct cnic_dev *dev)
 			(1 << SPE_HDR_COMMON_RAMROD_SHIFT), &l5_data);
 		msleep(10);
 	}
+	clear_bit(CNIC_LCL_FL_RINGS_INITED, &cp->cnic_local_flags);
 }
 
 static int cnic_start_hw(struct cnic_dev *dev)
diff --git a/drivers/net/cnic.h b/drivers/net/cnic.h
index 4827719..1797c62 100644
--- a/drivers/net/cnic.h
+++ b/drivers/net/cnic.h
@@ -183,6 +183,7 @@ struct cnic_local {
 	unsigned long cnic_local_flags;
 #define	CNIC_LCL_FL_KWQ_INIT		0x0
 #define	CNIC_LCL_FL_L2_WAIT		0x1
+#define	CNIC_LCL_FL_RINGS_INITED	0x2
 
 	struct cnic_dev *dev;