[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20090114111505.48d34949@hskinnemoen-d830>
Date: Wed, 14 Jan 2009 11:15:05 +0100
From: Haavard Skinnemoen <haavard.skinnemoen@...el.com>
To: Erik Waling <erik.waling@...ftel.se>
Cc: <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] macb: RLE and BNA handling
Erik Waling wrote:
> This patch (against 2.6.28) solves two issues we have been experiencing
> when connecting the EMAC module on our AT91SAM9260 board to an ethernet
> repeater hub. When transfering large amounts of data we sometimes
> experienced that the Retry Limit Exceeded (RLE) bit got set in TSR
> during transmission attempts. When this happened the driver would stall
> in a state that prevented any more data from being sent.
Right. This part of your patch looks good...
> The other issue experienced was in the RX part of the driver. Sometimes
> the driver runs out of unused slots in the RX ring buffer. All slots
> will be filled with data but the driver is not able to extract a
> complete frame from the fragments in the buffer. When this happens the
> Buffer Not Available (BNA) bit is set in RSR.
This part also looks like a real problem, however...
> @@ -527,18 +529,31 @@ static int macb_poll(struct napi_struct
> dev_dbg(&bp->pdev->dev, "poll: status = %08lx, budget = %d\n",
> (unsigned long)status, budget);
>
> - if (!(status & MACB_BIT(REC))) {
> + if (status & MACB_BIT(REC)) {
> + work_done = macb_rx(bp, budget);
> + if (work_done < budget)
> + netif_rx_complete(dev, napi);
> + } else if (status & MACB_BIT(BNA)) {
> + /* No slots available in RX ring. Mark all slots
> + * as unused.
> + */
> + int i;
> +
> + dev_warn(&bp->pdev->dev,
> + "No free RX buffers. Marking all as unused.\n");
> +
> + for (i = 0; i < RX_RING_SIZE; i++)
> + bp->rx_ring[i].addr &= ~MACB_BIT(RX_USED);
> +
> + wmb();
> + netif_rx_complete(dev, napi);
I'm not sure if nuking all the buffers that were received successfully
is the right thing to do here...?
> + } else if (!(status & MACB_BIT(REC))) {
This should probably be just "else", since you checked the REC bit
above.
Haavard
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists