Bug#764162: [PATCH 0/1] mv643xx_eth: Disable TSO by default

[Ian Campbell <ijc@hellion.org.uk>]

On Tue, 2014-11-04 at 15:20 +0100, Karl Beldan wrote:
> On Sat, Nov 01, 2014 at 12:30:19PM -0300, Ezequiel Garcia wrote:
> > Several users ([1], [2]) have been reporting data corruption with TSO on
> > Kirkwood platforms (i.e. using the mv643xx_eth driver).
> > 
> > Until we manage to find what's causing this, this simple patch will make
> > the TSO path disabled by default. This patch should be queued for stable,
> > fixing the TSO feature introduced in v3.16.
> > 
> > The corruption itself is very easy to reproduce: checking md5sum on a mounted
> > NFS directory gives a different result each time. Same tests using the mvneta
> > driver (Armada 370/38x/XP SoC) pass with no issues.
> > 
> > Frankly, I'm a bit puzzled about this, and so any ideas or debugging hints
> > are well received.
> > 
> 
> Hi,
> 
> Can you try this :

It fixes things for me, thanks!

Tested-by: Ian Campbell <ijc@hellion.org.uk>

> @@ -1067,7 +1082,8 @@ static int txq_reclaim(struct tx_queue *txq, int budget, int force)
>  		txq->tx_desc_count--;
>  
>  		skb = NULL;
> -		if (cmd_sts & TX_LAST_DESC)
> +		if ((cmd_sts & (TX_LAST_DESC | TX_ENABLE_INTERRUPT)) ==
> +			       (TX_LAST_DESC | TX_ENABLE_INTERRUPT))
>  			skb = __skb_dequeue(&txq->tx_skb);
>  
>  		if (cmd_sts & ERROR_SUMMARY) {
>