bnx2x: Allowing 0 as initial fairness value

Value of zero was used to disable the fairness mechanism. Though the code
(driver and FW) allowed changing the value at run time, it did not allow to do
that if the mechanism was disabled to begin with.
Fixed the FW to allow turning on and off the mechanism at run time. Fixed the
code to read the value from the chip at the right sequence.
Without this fix, if the initial value was set to zero, traffic could not run on
the interface.

Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bnx2x_main.c b/drivers/net/bnx2x_main.c
index b4e9c6e..691cf15 100644
--- a/drivers/net/bnx2x_main.c
+++ b/drivers/net/bnx2x_main.c
@@ -2333,8 +2333,14 @@
 	}
 
 	/* ... only if all min rates are zeros - disable fairness */
-	if (all_zero)
-		bp->vn_weight_sum = 0;
+	if (all_zero) {
+		bp->cmng.flags.cmng_enables &=
+					~CMNG_FLAGS_PER_PORT_FAIRNESS_VN;
+		DP(NETIF_MSG_IFUP, "All MIN values are zeroes"
+		   "  fairness will be disabled\n");
+	} else
+		bp->cmng.flags.cmng_enables |=
+					CMNG_FLAGS_PER_PORT_FAIRNESS_VN;
 }
 
 static void bnx2x_init_vn_minmax(struct bnx2x *bp, int func)
@@ -2353,17 +2359,14 @@
 	} else {
 		vn_min_rate = ((vn_cfg & FUNC_MF_CFG_MIN_BW_MASK) >>
 				FUNC_MF_CFG_MIN_BW_SHIFT) * 100;
-		/* If fairness is enabled (not all min rates are zeroes) and
-		   if current min rate is zero - set it to 1.
-		   This is a requirement of the algorithm. */
-		if (bp->vn_weight_sum && (vn_min_rate == 0))
+		/* If min rate is zero - set it to 1 */
+		if (!vn_min_rate)
 			vn_min_rate = DEF_MIN_RATE;
 		vn_max_rate = ((vn_cfg & FUNC_MF_CFG_MAX_BW_MASK) >>
 				FUNC_MF_CFG_MAX_BW_SHIFT) * 100;
 	}
-
 	DP(NETIF_MSG_IFUP,
-	   "func %d: vn_min_rate=%d  vn_max_rate=%d  vn_weight_sum=%d\n",
+	   "func %d: vn_min_rate %d  vn_max_rate %d  vn_weight_sum %d\n",
 	   func, vn_min_rate, vn_max_rate, bp->vn_weight_sum);
 
 	memset(&m_rs_vn, 0, sizeof(struct rate_shaping_vars_per_vn));
@@ -2490,7 +2493,6 @@
 	else
 		bnx2x_stats_handle(bp, STATS_EVENT_STOP);
 
-	bp->mf_config = SHMEM_RD(bp, mf_cfg.func_mf_config[func].config);
 	bnx2x_calc_vn_weight_sum(bp);
 
 	/* indicate link status */
@@ -2634,10 +2636,7 @@
 
 static void bnx2x_dcc_event(struct bnx2x *bp, u32 dcc_event)
 {
-	int func = BP_FUNC(bp);
-
 	DP(BNX2X_MSG_MCP, "dcc_event 0x%x\n", dcc_event);
-	bp->mf_config = SHMEM_RD(bp, mf_cfg.func_mf_config[func].config);
 
 	if (dcc_event & DRV_STATUS_DCC_DISABLE_ENABLE_PF) {
 
@@ -3067,6 +3066,8 @@
 			int func = BP_FUNC(bp);
 
 			REG_WR(bp, MISC_REG_AEU_GENERAL_ATTN_12 + func*4, 0);
+			bp->mf_config = SHMEM_RD(bp,
+					   mf_cfg.func_mf_config[func].config);
 			val = SHMEM_RD(bp, func_mb[func].drv_status);
 			if (val & DRV_STATUS_DCC_EVENT_MASK)
 				bnx2x_dcc_event(bp,
@@ -5559,20 +5560,18 @@
 		bp->link_vars.line_speed = SPEED_10000;
 		bnx2x_init_port_minmax(bp);
 
+		if (!BP_NOMCP(bp))
+			bp->mf_config =
+			      SHMEM_RD(bp, mf_cfg.func_mf_config[func].config);
 		bnx2x_calc_vn_weight_sum(bp);
 
 		for (vn = VN_0; vn < E1HVN_MAX; vn++)
 			bnx2x_init_vn_minmax(bp, 2*vn + port);
 
 		/* Enable rate shaping and fairness */
-		bp->cmng.flags.cmng_enables =
+		bp->cmng.flags.cmng_enables |=
 					CMNG_FLAGS_PER_PORT_RATE_SHAPING_VN;
-		if (bp->vn_weight_sum)
-			bp->cmng.flags.cmng_enables |=
-					CMNG_FLAGS_PER_PORT_FAIRNESS_VN;
-		else
-			DP(NETIF_MSG_IFUP, "All MIN values are zeroes"
-			   "  fairness will be disabled\n");
+
 	} else {
 		/* rate shaping and fairness are disabled */
 		DP(NETIF_MSG_IFUP,
@@ -9038,17 +9037,18 @@
 	if (netif_carrier_ok(dev)) {
 		cmd->speed = bp->link_vars.line_speed;
 		cmd->duplex = bp->link_vars.duplex;
-	} else {
-		cmd->speed = bp->link_params.req_line_speed;
-		cmd->duplex = bp->link_params.req_duplex;
-	}
-	if (IS_E1HMF(bp)) {
-		u16 vn_max_rate;
+		if (IS_E1HMF(bp)) {
+			u16 vn_max_rate;
 
-		vn_max_rate = ((bp->mf_config & FUNC_MF_CFG_MAX_BW_MASK) >>
+			vn_max_rate =
+				((bp->mf_config & FUNC_MF_CFG_MAX_BW_MASK) >>
 				FUNC_MF_CFG_MAX_BW_SHIFT) * 100;
-		if (vn_max_rate < cmd->speed)
-			cmd->speed = vn_max_rate;
+			if (vn_max_rate < cmd->speed)
+				cmd->speed = vn_max_rate;
+		}
+	} else {
+		cmd->speed = -1;
+		cmd->duplex = -1;
 	}
 
 	if (bp->link_params.switch_cfg == SWITCH_CFG_10G) {