From: David S. Miller <davem@davemloft.net>
Date: Tue, 9 Jun 2009 08:01:31 +0000 (-0700)
Subject: be2net: Remove unnecessary frag list traversing.
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=ebc8d2ab61dde6cf775ae7bb1ed9e38dfe12ca65;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git

be2net: Remove unnecessary frag list traversing.

This driver does not indicate support for frag lists.

Furthermore, even if it did, the code is walking the frag
lists incorrectly.  The idiom is:

	for (iter = skb_shinfo(skb)->frag_list; iter; iter = iter->next)

but it's doing:

	for (iter = skb_shinfo(skb)->frag_list; iter;
	     iter = skb_shinfo(iter)->frag_list)

which would never work.  And this proves that this driver never
saw an SKB with active frag lists.

So just remove the code altogether and the driver TX path becomes
much simpler.

Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/benet/be_main.c b/drivers/net/benet/be_main.c
index 5f17d80300a..347d002fa42 100644
--- a/drivers/net/benet/be_main.c
+++ b/drivers/net/benet/be_main.c
@@ -337,13 +337,10 @@ static void be_tx_stats_update(struct be_adapter *adapter,
 /* Determine number of WRB entries needed to xmit data in an skb */
 static u32 wrb_cnt_for_skb(struct sk_buff *skb, bool *dummy)
 {
-	int cnt = 0;
-	while (skb) {
-		if (skb->len > skb->data_len)
-			cnt++;
-		cnt += skb_shinfo(skb)->nr_frags;
-		skb = skb_shinfo(skb)->frag_list;
-	}
+	int cnt = (skb->len > skb->data_len);
+
+	cnt += skb_shinfo(skb)->nr_frags;
+
 	/* to account for hdr wrb */
 	cnt++;
 	if (cnt & 1) {
@@ -409,31 +406,28 @@ static int make_tx_wrbs(struct be_adapter *adapter,
 	hdr = queue_head_node(txq);
 	queue_head_inc(txq);
 
-	while (skb) {
-		if (skb->len > skb->data_len) {
-			int len = skb->len - skb->data_len;
-			busaddr = pci_map_single(pdev, skb->data, len,
-					PCI_DMA_TODEVICE);
-			wrb = queue_head_node(txq);
-			wrb_fill(wrb, busaddr, len);
-			be_dws_cpu_to_le(wrb, sizeof(*wrb));
-			queue_head_inc(txq);
-			copied += len;
-		}
+	if (skb->len > skb->data_len) {
+		int len = skb->len - skb->data_len;
+		busaddr = pci_map_single(pdev, skb->data, len,
+					 PCI_DMA_TODEVICE);
+		wrb = queue_head_node(txq);
+		wrb_fill(wrb, busaddr, len);
+		be_dws_cpu_to_le(wrb, sizeof(*wrb));
+		queue_head_inc(txq);
+		copied += len;
+	}
 
-		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
-			struct skb_frag_struct *frag =
-				&skb_shinfo(skb)->frags[i];
-			busaddr = pci_map_page(pdev, frag->page,
-					frag->page_offset,
-					frag->size, PCI_DMA_TODEVICE);
-			wrb = queue_head_node(txq);
-			wrb_fill(wrb, busaddr, frag->size);
-			be_dws_cpu_to_le(wrb, sizeof(*wrb));
-			queue_head_inc(txq);
-			copied += frag->size;
-		}
-		skb = skb_shinfo(skb)->frag_list;
+	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+		struct skb_frag_struct *frag =
+			&skb_shinfo(skb)->frags[i];
+		busaddr = pci_map_page(pdev, frag->page,
+				       frag->page_offset,
+				       frag->size, PCI_DMA_TODEVICE);
+		wrb = queue_head_node(txq);
+		wrb_fill(wrb, busaddr, frag->size);
+		be_dws_cpu_to_le(wrb, sizeof(*wrb));
+		queue_head_inc(txq);
+		copied += frag->size;
 	}
 
 	if (dummy_wrb) {