On Mon, Jan 16, 2017 at 11:41:51PM +0300, Sergei Shtylyov wrote:
> Hello!
>
> On 01/12/2017 04:18 PM, Simon Horman wrote:
>
> >...
>
> >>>> Here, it stop once an untransmitted buffer is encountered...
> >>>
> >>>Yes, I see that now.
> >>>
> >>>I wonder if we should:
> >>>
> >>>a) paramatise ravb_tx_free() so it may either clear all transmitted buffers
> >>> (current behaviour) or all buffers (new behaviour).
> >>>b) provide a different version of this loop in ravb_ring_free()
> >>>
> >>>What are your thoughts?
> >>
> >> I'm voting for (b).
>
> After looking at this issue for another time, I'll vote for (a). Sorry
> for back-and-forth on this matter -- I somehow thought we could do a better
> job by scanning all the TX ring...
No problem. I also have had several opinions on this over time.
I'll see about respinning the patch.
>
> >Ok, something like this?
> >
> >@@ -215,6 +225,30 @@ static void ravb_ring_free(struct net_device *ndev, int q)
> > }
> >
> > if (priv->tx_ring[q]) {
> >+ for (; priv->cur_tx[q] - priv->dirty_tx[q] > 0; priv->dirty_tx[q]++) {
> >+ struct ravb_tx_desc *desc;
> >+ int entry;
> >+
> >+ entry = priv->dirty_tx[q] % (priv->num_tx_ring[q] *
> >+ NUM_TX_DESC);
> >+ desc = &priv->tx_ring[q][entry];
> >+
> >+ /* Free the original skb. */
> >+ if (priv->tx_skb[q][entry / NUM_TX_DESC]) {
> >+ u32 size = le16_to_cpu(desc->ds_tagl) & TX_DS;
> >+
> >+ dma_unmap_single(ndev->dev.parent,
> >+ le32_to_cpu(desc->dptr),
> >+ size, DMA_TO_DEVICE);
> >+ /* Last packet descriptor? */
> >+ if (entry % NUM_TX_DESC == NUM_TX_DESC - 1) {
> >+ entry /= NUM_TX_DESC;
> >+ dev_kfree_skb_any(priv->tx_skb[q][entry]);
> >+ priv->tx_skb[q][entry] = NULL;
> >+ }
> >+ }
> >+ }
> >+
>
> This is only different from ravb_tx_free() by not stopping on unfinished
> descriptor, so we must be good with adding an extra param to it...
>
> [...]
>
> MBR, Sergei
>
