[PATCH 2.6.13-rc4 12/13] S2io: Miscellaneous fixes

[raghavendra.koushik@neterion.com]

Hi,
The last patch in this series fixes the following issues found during
testing.
1. Ensure we don't pass zero sized buffers to the card(which can lockup) 
2. Restore the PCI-X parameters(in case of Xframe I adapter) after a reset.
3. Make sure total size of all FIFOs does not exceed 8192.

Signed-off-by: Ravinandan Arakali <ravinandan.arakali@neterion.com>
Signed-off-by: Raghavendra Koushik <raghavendra.koushik@neterion.com>
---
diff -uprN vanilla_linux/drivers/net/s2io.c linux-2.6.13-rc4/drivers/net/s2io.c
--- vanilla_linux/drivers/net/s2io.c	2005-08-02 07:05:12.000000000 -0700
+++ linux-2.6.13-rc4/drivers/net/s2io.c	2005-08-02 07:05:24.000000000 -0700
@@ -365,10 +365,9 @@ static int init_shared_mem(struct s2io_n
 		size += config->tx_cfg[i].fifo_len;
 	}
 	if (size > MAX_AVAILABLE_TXDS) {
-		DBG_PRINT(ERR_DBG, "%s: Total number of Tx FIFOs ",
-			  dev->name);
-		DBG_PRINT(ERR_DBG, "exceeds the maximum value ");
-		DBG_PRINT(ERR_DBG, "that can be used\n");
+		DBG_PRINT(ERR_DBG, "%s: Requested TxDs too high, ",
+			  __FUNCTION__);
+		DBG_PRINT(ERR_DBG, "Requested: %d, max supported: 8192\n", size);
 		return FAILURE;
 	}
 
@@ -611,8 +610,9 @@ static void free_shared_mem(struct s2io_
 						lst_per_page);
 		for (j = 0; j < page_num; j++) {
 			int mem_blks = (j * lst_per_page);
-			if (!mac_control->fifos[i].list_info[mem_blks].
-			    list_virt_addr)
+			if ((!mac_control->fifos[i].list_info) ||
+				(!mac_control->fifos[i].list_info[mem_blks].
+				 list_virt_addr))
 				break;
 			pci_free_consistent(nic->pdev, PAGE_SIZE,
 					    mac_control->fifos[i].
@@ -2594,6 +2594,8 @@ static void tx_intr_handler(fifo_info_t 
 			for (j = 0; j < frg_cnt; j++, txdlp++) {
 				skb_frag_t *frag =
 				    &skb_shinfo(skb)->frags[j];
+				if (!txdlp->Buffer_Pointer)
+					break;
 				pci_unmap_page(nic->pdev,
 					       (dma_addr_t)
 					       txdlp->
@@ -2744,6 +2746,10 @@ void s2io_reset(nic_t * sp)
 	u64 val64;
 	u16 subid, pci_cmd;
 
+	/* Back up  the PCI-X CMD reg, dont want to lose MMRBC, OST settings */
+	if (sp->device_type == XFRAME_I_DEVICE)
+		pci_read_config_word(sp->pdev, PCIX_COMMAND_REGISTER, &(pci_cmd));
+
 	val64 = SW_RESET_ALL;
 	writeq(val64, &bar0->sw_reset);
 
@@ -2762,8 +2768,10 @@ void s2io_reset(nic_t * sp)
 	msleep(250);
 
 	if (!(sp->device_type & XFRAME_II_DEVICE)) {
-	/* Restore the PCI state saved during initializarion. */
+		/* Restore the PCI state saved during initializarion. */
 		pci_restore_state(sp->pdev);
+		pci_write_config_word(sp->pdev, PCIX_COMMAND_REGISTER,
+				     pci_cmd);
 	} else {
 		pci_set_master(sp->pdev);
 	}
@@ -2974,7 +2982,7 @@ int s2io_open(struct net_device *dev)
 	 * Nic is initialized
 	 */
 	netif_carrier_off(dev);
-	sp->last_link_state = LINK_DOWN;
+	sp->last_link_state = 0;
 
 	/* Initialize H/W and enable interrupts */
 	if (s2io_card_up(sp)) {
@@ -3102,6 +3110,15 @@ int s2io_xmit(struct sk_buff *skb, struc
 		spin_unlock_irqrestore(&sp->tx_lock, flags);
 		return 0;
 	}
+
+	/* A buffer with no data will be dropped */
+	if (!skb->len) {
+		DBG_PRINT(TX_DBG, "%s:Buffer has no data..\n", dev->name);
+		dev_kfree_skb(skb);
+		spin_unlock_irqrestore(&sp->tx_lock, flags);
+		return 0;
+	}
+
 #ifdef NETIF_F_TSO
 	mss = skb_shinfo(skb)->tso_size;
 	if (mss) {
@@ -3136,6 +3153,9 @@ int s2io_xmit(struct sk_buff *skb, struc
 	/* For fragmented SKB. */
 	for (i = 0; i < frg_cnt; i++) {
 		skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+		/* A '0' length fragment will be ignored */
+		if (!frag->size)
+			continue;
 		txdp++;
 		txdp->Buffer_Pointer = (u64) pci_map_page
 		    (sp->pdev, frag->page, frag->page_offset,
@@ -5257,7 +5277,8 @@ s2io_init_nic(struct pci_dev *pdev, cons
 	config = &sp->config;
 
 	/* Tx side parameters. */
-	tx_fifo_len[0] = DEFAULT_FIFO_LEN;	/* Default value. */
+	if (tx_fifo_len[0] == 0)
+		tx_fifo_len[0] = DEFAULT_FIFO_LEN; /* Default value. */
 	config->tx_fifo_num = tx_fifo_num;
 	for (i = 0; i < MAX_TX_FIFOS; i++) {
 		config->tx_cfg[i].fifo_len = tx_fifo_len[i];
@@ -5280,7 +5301,8 @@ s2io_init_nic(struct pci_dev *pdev, cons
 	config->max_txds = MAX_SKB_FRAGS;
 
 	/* Rx side parameters. */
-	rx_ring_sz[0] = SMALL_BLK_CNT;	/* Default value. */
+	if (rx_ring_sz[0] == 0)
+		rx_ring_sz[0] = SMALL_BLK_CNT; /* Default value. */
 	config->rx_ring_num = rx_ring_num;
 	for (i = 0; i < MAX_RX_RINGS; i++) {
 		config->rx_cfg[i].num_rxd = rx_ring_sz[i] *
@@ -5310,7 +5332,7 @@ s2io_init_nic(struct pci_dev *pdev, cons
 	/*  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",
-			  dev->name);
+			  __FUNCTION__);
 		ret = -ENOMEM;
 		goto mem_alloc_failed;
 	}
@@ -5488,7 +5510,7 @@ s2io_init_nic(struct pci_dev *pdev, cons
 			  sp->def_mac_addr[0].mac_addr[3],
 			  sp->def_mac_addr[0].mac_addr[4],
 			  sp->def_mac_addr[0].mac_addr[5]);
-		int mode = s2io_print_pci_mode(sp);
+		mode = s2io_print_pci_mode(sp);
 		if (mode < 0) {
 			DBG_PRINT(ERR_DBG, " Unsupported PCI bus mode ");
 			ret = -EBADSLT;