| Submitter | Andreas Oberritter |
|---|---|
| Date | Oct. 8, 2008, 7:44 a.m. |
| Message ID | <48EC64E1.5070806@linuxtv.org> |
| Download | mbox | patch |
| Permalink | /patch/3274/ |
| State | Superseded |
| Delegated to: | Jeff Garzik |
| Headers | show |
Comments
Andreas Oberritter wrote: > From: Andreas Oberritter <obi@linuxtv.org> > > The write barrier should be used before starting a DMA transfer. This fixes > a problem, where almost all packets received on another machine had garbled > content. Tested with an RTL8100C on a MIPS machine. > > Signed-off-by: Andreas Oberritter <obi@linuxtv.org> > > diff --git a/drivers/net/8139too.c b/drivers/net/8139too.c > index 53bd903..44344af 100644 > --- a/drivers/net/8139too.c > +++ b/drivers/net/8139too.c > @@ -1716,13 +1716,13 @@ static int rtl8139_start_xmit (struct sk_buff *skb, struct net_device *dev) > } > > spin_lock_irqsave(&tp->lock, flags); > + wmb(); [...] All memory barriers need a comment to explain why and what they're doing. Ben.
Patch
diff --git a/drivers/net/8139too.c b/drivers/net/8139too.c index 53bd903..44344af 100644 --- a/drivers/net/8139too.c +++ b/drivers/net/8139too.c @@ -1716,13 +1716,13 @@ static int rtl8139_start_xmit (struct sk_buff *skb, struct net_device *dev) } spin_lock_irqsave(&tp->lock, flags); + wmb(); RTL_W32_F (TxStatus0 + (entry * sizeof (u32)), tp->tx_flag | max(len, (unsigned int)ETH_ZLEN)); dev->trans_start = jiffies; tp->cur_tx++; - wmb(); if ((tp->cur_tx - NUM_TX_DESC) == tp->dirty_tx) netif_stop_queue (dev);