[PATCH] S2io: Miscellaneous fixes

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>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
diff --git a/drivers/net/s2io.c b/drivers/net/s2io.c
index e7c4285..abf910e 100644
--- a/drivers/net/s2io.c
+++ b/drivers/net/s2io.c
@@ -365,10 +365,9 @@
 		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 @@
 						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 @@
 			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 @@
 	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 @@
 	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 @@
 	 * 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 @@
 		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 @@
 	/* 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 @@
 	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 @@
 	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 @@
 	/*  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 @@
 			  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;