jme: Fix unmap loop counting error:

In my recent fix (76a691d0a: fix dma unmap warning), Ben Hutchings noted that my
loop count was incorrect.  Where j started at startidx, it should have started
at zero, and gone on for count entries, not to endidx.  Additionally, a DMA
resource exhaustion should drop the frame and (for now), return
NETDEV_TX_OK, not NETEV_TX_BUSY.  This patch fixes both of those issues:

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Ben Hutchings <ben@decadent.org.uk>
CC: "David S. Miller" <davem@davemloft.net>
CC: Guo-Fu Tseng <cooldavid@cooldavid.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/jme.c b/drivers/net/ethernet/jme.c
index 6e664d9038d60df53b36b3869897cb49582fca16..b78378cea5e39b6e18627b9f39ac5249c40293fd 100644 (file)
--- a/drivers/net/ethernet/jme.c
+++ b/drivers/net/ethernet/jme.c
@@ -2027,14 +2027,14 @@ jme_fill_tx_map(struct pci_dev *pdev,
        return 0;
 }
 
-static void jme_drop_tx_map(struct jme_adapter *jme, int startidx, int endidx)
+static void jme_drop_tx_map(struct jme_adapter *jme, int startidx, int count)
 {
        struct jme_ring *txring = &(jme->txring[0]);
        struct jme_buffer_info *txbi = txring->bufinf, *ctxbi;
        int mask = jme->tx_ring_mask;
        int j;
 
-       for (j = startidx ; j < endidx ; ++j) {
+       for (j = 0 ; j < count ; j++) {
                ctxbi = txbi + ((startidx + j + 2) & (mask));
                pci_unmap_page(jme->pdev,
                                ctxbi->mapping,
@@ -2069,7 +2069,7 @@ jme_map_tx_skb(struct jme_adapter *jme, struct sk_buff *skb, int idx)
                                skb_frag_page(frag),
                                frag->page_offset, skb_frag_size(frag), hidma);
                if (ret) {
-                       jme_drop_tx_map(jme, idx, idx+i);
+                       jme_drop_tx_map(jme, idx, i);
                        goto out;
                }
 
@@ -2081,7 +2081,7 @@ jme_map_tx_skb(struct jme_adapter *jme, struct sk_buff *skb, int idx)
        ret = jme_fill_tx_map(jme->pdev, ctxdesc, ctxbi, virt_to_page(skb->data),
                        offset_in_page(skb->data), len, hidma);
        if (ret)
-               jme_drop_tx_map(jme, idx, idx+i);
+               jme_drop_tx_map(jme, idx, i);
 
 out:
        return ret;
@@ -2269,7 +2269,7 @@ jme_start_xmit(struct sk_buff *skb, struct net_device *netdev)
        }
 
        if (jme_fill_tx_desc(jme, skb, idx))
-               return NETDEV_TX_BUSY;
+               return NETDEV_TX_OK;
 
        jwrite32(jme, JME_TXCS, jme->reg_txcs |
                                TXCS_SELECT_QUEUE0 |