Commit d65d2b25 authored by Malcolm Priestley's avatar Malcolm Priestley Committed by Greg Kroah-Hartman

staging: vt6655: vnt_tx_packet Correct TX order of OWNED_BY_NIC

The state of m_td0TD0.f1Owner should change after the buff_addr
has been filled otherwise the device grabs the buffer too early.

m_td0TD0.f1Owner is protected by memory barriers on both sides
of change.

iTDUsed is best incremented after MACvTransmit.

It appears that f1Owner actually polls to do the memory transfer.

A back port patch will be needed for v3.19
Signed-off-by: default avatarMalcolm Priestley <tvboxspy@gmail.com>
Cc: <stable@vger.kernel.org> # v4.0+
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ad3fee9b
...@@ -1206,14 +1206,6 @@ static int vnt_tx_packet(struct vnt_private *priv, struct sk_buff *skb) ...@@ -1206,14 +1206,6 @@ static int vnt_tx_packet(struct vnt_private *priv, struct sk_buff *skb)
if (dma_idx == TYPE_AC0DMA) if (dma_idx == TYPE_AC0DMA)
head_td->pTDInfo->byFlags = TD_FLAGS_NETIF_SKB; head_td->pTDInfo->byFlags = TD_FLAGS_NETIF_SKB;
priv->iTDUsed[dma_idx]++;
/* Take ownership */
wmb();
head_td->m_td0TD0.f1Owner = OWNED_BY_NIC;
/* get Next */
wmb();
priv->apCurrTD[dma_idx] = head_td->next; priv->apCurrTD[dma_idx] = head_td->next;
spin_unlock_irqrestore(&priv->lock, flags); spin_unlock_irqrestore(&priv->lock, flags);
...@@ -1234,11 +1226,18 @@ static int vnt_tx_packet(struct vnt_private *priv, struct sk_buff *skb) ...@@ -1234,11 +1226,18 @@ static int vnt_tx_packet(struct vnt_private *priv, struct sk_buff *skb)
head_td->buff_addr = cpu_to_le32(head_td->pTDInfo->skb_dma); head_td->buff_addr = cpu_to_le32(head_td->pTDInfo->skb_dma);
/* Poll Transmit the adapter */
wmb();
head_td->m_td0TD0.f1Owner = OWNED_BY_NIC;
wmb(); /* second memory barrier */
if (head_td->pTDInfo->byFlags & TD_FLAGS_NETIF_SKB) if (head_td->pTDInfo->byFlags & TD_FLAGS_NETIF_SKB)
MACvTransmitAC0(priv->PortOffset); MACvTransmitAC0(priv->PortOffset);
else else
MACvTransmit0(priv->PortOffset); MACvTransmit0(priv->PortOffset);
priv->iTDUsed[dma_idx]++;
spin_unlock_irqrestore(&priv->lock, flags); spin_unlock_irqrestore(&priv->lock, flags);
return 0; return 0;
......
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