Subject: Re: [PATCH] net/can/mscan: Enable interrupts when all TX buffers are occupied to get notified when they are available again

From: Wolfgang Grandegger <[email-masked]>
Date: Mon, 28 Nov 2011 14:37:53 +0100

On 11/28/2011 02:25 PM, Mosler, Martin wrote:
> When all TX buffers of the mscan are occupied the network layer is told to stop sending further packets. However the TX interrupts are not enabled and therefore the driver has no chance to tell the network layer when it is ready to accept further packets.
> 
> Signed-off-by: Martin Mosler <[email-masked]>
> 
> --- linux-2.6/drivers/net/can/mscan/mscan.c.orig    2011-11-28 13:54:29.547850661 +0100
> +++ linux-2.6/drivers/net/can/mscan/mscan.c 2011-11-28 13:55:52.427849601 +0100
> @@ -214,6 +214,7 @@ static netdev_tx_t mscan_start_xmit(stru
>     case 0:
>         netif_stop_queue(dev);
>         dev_err(dev->dev.parent, "Tx Ring full when queue awake!\n");
> +       out_8(&regs->cantier, priv->tx_active);
>         return NETDEV_TX_BUSY;
>     case 1:
>         /*  

Hm, did you see the error message. Actually, it should never happen, IIRC.

Wolfgang.