DaVinci platform unable to boot via NFS

[nsekhar@ti.com (Sekhar Nori)]

Prabhakar,

On 3/15/2013 7:11 PM, Prabhakar Lad wrote:
> Hi Mugunthan,
> 
> With 3.9 release I am not able to boot any davinci board via nfs, finally
> digging Into I found that there were recent changes for Ethernet davinci.
> Finally I reverting this to some safe commit I was able to boot via nfs.
> I reverted back as following:-
> git checkout  f9a8f83b04e0c362a2fc660dbad980d24af209fc  drivers/net/ethernet/ti/
> 
> Can you please take a look at and fix it.
> 
> Cheers,
> --Prabhakar Lad
> http://in.linkedin.com/pub/prabhakar-lad/19/92b/955
> 

A similar bug was reported on cpsw and the following patch from Daniel 
seems to have helped.

https://git.kernel.org/cgit/linux/kernel/git/davem/net.git/commit/?id=d35162f89b8f00537d7b240b76d2d0e8b8d29aa0

I made a similar fix for davinci_emac.c and the resulting diff is below 
(not tested or built).

Can you please check if this helps in DaVinci case?

Thanks,
Sekhar

----8<----
diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
index 52c0536..ae1b77a 100644
--- a/drivers/net/ethernet/ti/davinci_emac.c
+++ b/drivers/net/ethernet/ti/davinci_emac.c
@@ -1102,7 +1102,7 @@ static int emac_dev_xmit(struct sk_buff *skb, struct net_device *ndev)
        /* If there is no more tx desc left free then we need to
         * tell the kernel to stop sending us tx frames.
         */
-       if (unlikely(cpdma_check_free_tx_desc(priv->txchan)))
+       if (unlikely(!cpdma_check_free_tx_desc(priv->txchan)))
                netif_stop_queue(ndev);

        return NETDEV_TX_OK;