[PATCH] S2io: Software fixes

Hi,
Below patch includes fixes for few purely software bugs identified
since last release.
1. Keep track and display(as part of ethtool command output) the no.
   of single-bit and double-bit ECC errors.
2. Handle race condition between intr handler and "interface down"
   routine.
3. Initial link state setting modified so that the link state displayed
   after "interface Up" is correct.
4. Fix for "Incorrect Tx packet count when TSO is enabled".
5. Disable periodic DMA of statistics and schedule one-shot DMA
   only when required.

Signed-off-by: Ravinandan Arakali <ravinandan.arakali@neterion.com>
Signed-off-by: Raghavendra Koushik <raghavendra.koushik@neterion.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index e2144fc..e24c5e5 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -158,6 +158,9 @@
 	{"rmac_pause_cnt"},
 	{"rmac_accepted_ip"},
 	{"rmac_err_tcp"},
+	{"\n DRIVER STATISTICS"},
+	{"single_bit_ecc_errs"},
+	{"double_bit_ecc_errs"},
 };
 
 #define S2IO_STAT_LEN sizeof(ethtool_stats_keys)/ ETH_GSTRING_LEN
@@ -237,7 +240,6 @@
 static unsigned int rx_ring_num = 1;
 static unsigned int rx_ring_sz[MAX_RX_RINGS] =
     {[0 ...(MAX_RX_RINGS - 1)] = 0 };
-static unsigned int Stats_refresh_time = 4;
 static unsigned int rts_frm_len[MAX_RX_RINGS] =
     {[0 ...(MAX_RX_RINGS - 1)] = 0 };
 static unsigned int use_continuous_tx_intrs = 1;
@@ -1083,9 +1085,6 @@
 
 	/* Program statistics memory */
 	writeq(mac_control->stats_mem_phy, &bar0->stat_addr);
-	val64 = SET_UPDT_PERIOD(Stats_refresh_time) |
-		STAT_CFG_STAT_RO | STAT_CFG_STAT_EN;
-	writeq(val64, &bar0->stat_cfg);
 
 	/*
 	 * Initializing the sampling rate for the device to calculate the
@@ -2101,6 +2100,7 @@
 	u64 val64;
 	int i;
 
+	atomic_inc(&nic->isr_cnt);
 	mac_control = &nic->mac_control;
 	config = &nic->config;
 
@@ -2136,6 +2136,7 @@
 	}
 	/* Re enable the Rx interrupts. */
 	en_dis_able_nic_intrs(nic, RX_TRAFFIC_INTR, ENABLE_INTRS);
+	atomic_dec(&nic->isr_cnt);
 	return 0;
 
 no_rx:
@@ -2149,6 +2150,7 @@
 			break;
 		}
 	}
+	atomic_dec(&nic->isr_cnt);
 	return 1;
 }
 #endif
@@ -2179,6 +2181,13 @@
 #endif
 	register u64 val64;
 
+	spin_lock(&nic->rx_lock);
+	if (atomic_read(&nic->card_state) == CARD_DOWN) {
+		DBG_PRINT(ERR_DBG, "%s: %s going down for reset\n",
+			  __FUNCTION__, dev->name);
+		spin_unlock(&nic->rx_lock);
+	}
+
 	/*
 	 * rx_traffic_int reg is an R1 register, hence we read and write
 	 * back the same value in the register to clear it
@@ -2210,6 +2219,7 @@
 			DBG_PRINT(ERR_DBG, "%s: The skb is ",
 				  dev->name);
 			DBG_PRINT(ERR_DBG, "Null in Rx Intr\n");
+			spin_unlock(&nic->rx_lock);
 			return;
 		}
 #ifndef CONFIG_2BUFF_MODE
@@ -2262,6 +2272,7 @@
 			break;
 #endif
 	}
+	spin_unlock(&nic->rx_lock);
 }
 
 /**
@@ -2345,7 +2356,6 @@
 		       (sizeof(TxD_t) * fifo_data->max_txds));
 
 		/* Updating the statistics block */
-		nic->stats.tx_packets++;
 		nic->stats.tx_bytes += skb->len;
 		dev_kfree_skb_irq(skb);
 
@@ -2393,13 +2403,16 @@
 	writeq(val64, &bar0->mc_err_reg);
 	if (val64 & (MC_ERR_REG_ECC_ALL_SNG | MC_ERR_REG_ECC_ALL_DBL)) {
 		if (val64 & MC_ERR_REG_ECC_ALL_DBL) {
+			nic->mac_control.stats_info->sw_stat.
+				double_ecc_errs++;
 			DBG_PRINT(ERR_DBG, "%s: Device indicates ",
 				  dev->name);
 			DBG_PRINT(ERR_DBG, "double ECC error!!\n");
 			netif_stop_queue(dev);
 			schedule_work(&nic->rst_timer_task);
 		} else {
-			/* Device can recover from Single ECC errors */
+			nic->mac_control.stats_info->sw_stat.
+				single_ecc_errs++;
 		}
 	}
 
@@ -2695,7 +2708,7 @@
 	 * Nic is initialized
 	 */
 	netif_carrier_off(dev);
-	sp->last_link_state = LINK_DOWN;
+	sp->last_link_state = 0; /* Unkown link state */
 
 	/* Initialize H/W and enable interrupts */
 	if (s2io_card_up(sp)) {
@@ -2909,6 +2922,7 @@
 	mac_info_t *mac_control;
 	struct config_param *config;
 
+	atomic_inc(&sp->isr_cnt);
 	mac_control = &sp->mac_control;
 	config = &sp->config;
 
@@ -2924,6 +2938,7 @@
 
 	if (!reason) {
 		/* The interrupt was not raised by Xena. */
+		atomic_dec(&sp->isr_cnt);
 		return IRQ_NONE;
 	}
 
@@ -2972,6 +2987,7 @@
 					  dev->name);
 				DBG_PRINT(ERR_DBG, " in ISR!!\n");
 				clear_bit(0, (&sp->tasklet_status));
+				atomic_dec(&sp->isr_cnt);
 				return IRQ_HANDLED;
 			}
 			clear_bit(0, (&sp->tasklet_status));
@@ -2981,10 +2997,37 @@
 	}
 #endif
 
+	atomic_dec(&sp->isr_cnt);
 	return IRQ_HANDLED;
 }
 
 /**
+ * s2io_updt_stats -
+ */
+static void s2io_updt_stats(nic_t *sp)
+{
+	XENA_dev_config_t __iomem *bar0 = sp->bar0;
+	u64 val64;
+	int cnt = 0;
+
+	if (atomic_read(&sp->card_state) == CARD_UP) {
+		/* Apprx 30us on a 133 MHz bus */
+		val64 = SET_UPDT_CLICKS(10) |
+			STAT_CFG_ONE_SHOT_EN | STAT_CFG_STAT_EN;
+		writeq(val64, &bar0->stat_cfg);
+		do {
+			udelay(100);
+			val64 = readq(&bar0->stat_cfg);
+			if (!(val64 & BIT(0)))
+				break;
+			cnt++;
+			if (cnt == 5)
+				break; /* Updt failed */
+		} while(1);
+	}
+}
+
+/**
  *  s2io_get_stats - Updates the device statistics structure.
  *  @dev : pointer to the device structure.
  *  Description:
@@ -3004,6 +3047,11 @@
 	mac_control = &sp->mac_control;
 	config = &sp->config;
 
+	/* Configure Stats for immediate updt */
+	s2io_updt_stats(sp);
+
+	sp->stats.tx_packets =
+		le32_to_cpu(mac_control->stats_info->tmac_frms);
 	sp->stats.tx_errors =
 		le32_to_cpu(mac_control->stats_info->tmac_any_err_frms);
 	sp->stats.rx_errors =
@@ -4018,6 +4066,7 @@
 	nic_t *sp = dev->priv;
 	StatInfo_t *stat_info = sp->mac_control.stats_info;
 
+	s2io_updt_stats(sp);
 	tmp_stats[i++] = le32_to_cpu(stat_info->tmac_frms);
 	tmp_stats[i++] = le32_to_cpu(stat_info->tmac_data_octets);
 	tmp_stats[i++] = le64_to_cpu(stat_info->tmac_drop_frms);
@@ -4057,6 +4106,9 @@
 	tmp_stats[i++] = le32_to_cpu(stat_info->rmac_pause_cnt);
 	tmp_stats[i++] = le32_to_cpu(stat_info->rmac_accepted_ip);
 	tmp_stats[i++] = le32_to_cpu(stat_info->rmac_err_tcp);
+	tmp_stats[i++] = 0;
+	tmp_stats[i++] = stat_info->sw_stat.single_ecc_errs;
+	tmp_stats[i++] = stat_info->sw_stat.double_ecc_errs;
 }
 
 int s2io_ethtool_get_regs_len(struct net_device *dev)
@@ -4353,14 +4405,27 @@
 			break;
 		}
 	} while (1);
-	spin_lock_irqsave(&sp->tx_lock, flags);
 	s2io_reset(sp);
 
-	/* Free all unused Tx and Rx buffers */
-	free_tx_buffers(sp);
-	free_rx_buffers(sp);
+	/* Waiting till all Interrupt handlers are complete */
+	cnt = 0;
+	do {
+		msleep(10);
+		if (!atomic_read(&sp->isr_cnt))
+			break;
+		cnt++;
+	} while(cnt < 5);
 
+	spin_lock_irqsave(&sp->tx_lock, flags);
+	/* Free all Tx buffers */
+	free_tx_buffers(sp);
 	spin_unlock_irqrestore(&sp->tx_lock, flags);
+
+	/* Free all Rx buffers */
+	spin_lock_irqsave(&sp->rx_lock, flags);
+	free_rx_buffers(sp);
+	spin_unlock_irqrestore(&sp->rx_lock, flags);
+
 	clear_bit(0, &(sp->link_state));
 }
 
@@ -4647,7 +4712,6 @@
 module_param(rx_ring_num, int, 0);
 module_param_array(tx_fifo_len, uint, NULL, 0);
 module_param_array(rx_ring_sz, uint, NULL, 0);
-module_param(Stats_refresh_time, int, 0);
 module_param_array(rts_frm_len, uint, NULL, 0);
 module_param(use_continuous_tx_intrs, int, 1);
 module_param(rmac_pause_time, int, 0);
@@ -4804,6 +4868,9 @@
 	for (i = 0; i < config->rx_ring_num; i++)
 		atomic_set(&sp->rx_bufs_left[i], 0);
 
+	/* Initialize the number of ISRs currently running */
+	atomic_set(&sp->isr_cnt, 0);
+
 	/*  initialize the shared memory used by the NIC and the host */
 	if (init_shared_mem(sp)) {
 		DBG_PRINT(ERR_DBG, "%s: Memory allocation failed\n",
@@ -4938,6 +5005,7 @@
 #ifndef CONFIG_S2IO_NAPI
 	spin_lock_init(&sp->put_lock);
 #endif
+	spin_lock_init(&sp->rx_lock);
 
 	/*
 	 * SXE-002: Configure link and activity LED to init state
@@ -4961,13 +5029,16 @@
 		goto register_failed;
 	}
 
+	/* Initialize device name */
+	strcpy(sp->name, dev->name);
+	strcat(sp->name, ": Neterion Xframe I 10GbE adapter");
+
 	/*
 	 * Make Link state as off at this point, when the Link change
 	 * interrupt comes the state will be automatically changed to
 	 * the right state.
 	 */
 	netif_carrier_off(dev);
-	sp->last_link_state = LINK_DOWN;
 
 	return 0;
 
diff --git a/drivers/net/s2io.h b/drivers/net/s2io.h
index 92db59a..69dd0e5 100644
--- a/drivers/net/s2io.h
+++ b/drivers/net/s2io.h
@@ -195,6 +195,9 @@
 	u32 rxd_rd_cnt;
 	u32 rxf_wr_cnt;
 	u32 txf_rd_cnt;
+
+/* Software statistics maintained by driver */
+	swStat_t sw_stat;
 } StatInfo_t;
 
 /*
@@ -678,6 +681,8 @@
 #define CARD_UP 2
 	atomic_t card_state;
 	volatile unsigned long link_state;
+	spinlock_t	rx_lock;
+	atomic_t	isr_cnt;
 };
 
 #define RESET_ERROR 1;