diff options
| author | Malcolm Priestley <tvboxspy@gmail.com> | 2015-04-21 22:33:00 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-06-06 08:20:59 -0700 |
| commit | 644bea7497c0f7072ec71a90f051ab311f04ca17 (patch) | |
| tree | 8149b1c0fdb4b558e23761d81ced856237dac900 | |
| parent | 99681c40cf1568eb0b8e708ade687a305641293d (diff) | |
staging: vt6655: vnt_tx_packet Correct TX order of OWNED_BY_NIC
commit d65d2b25d2761153390df8026cca1a528d9b6c5a upstream.
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: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/vt6655/device_main.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/drivers/staging/vt6655/device_main.c b/drivers/staging/vt6655/device_main.c index d7466c603d42..584fc36a99c0 100644 --- a/drivers/staging/vt6655/device_main.c +++ b/drivers/staging/vt6655/device_main.c @@ -1203,14 +1203,6 @@ static int vnt_tx_packet(struct vnt_private *priv, struct sk_buff *skb) if (dma_idx == TYPE_AC0DMA) 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; spin_unlock_irqrestore(&priv->lock, flags); @@ -1231,11 +1223,18 @@ 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); + /* 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) MACvTransmitAC0(priv->PortOffset); else MACvTransmit0(priv->PortOffset); + priv->iTDUsed[dma_idx]++; + spin_unlock_irqrestore(&priv->lock, flags); return 0; |