Hi Simon,
Until now it seems to work. No issues so far.
Regards and Thanks
Sven
Am Thu, 9 Nov 2017 20:19:42 +0100
schrieb Andreas Tobler <andreas.tob...@cloudguard.ch>:
> Hi Simon,
>
>
> On 08.11.17 18:17, Simon Guinot wrote:
> > Hi Sven and Andreas,
> >
> > Please, can you try with this patch ?
>
> Today we, my son and I, repeated the failing scenario and we were
> able to show that our scenario behaves stable after you patch being
> applied.
>
> Thanks for taking care of this issue. If you need further testing let
> me know.
>
> Regards,
> Andreas
>
> > On Wed, Nov 08, 2017 at 05:58:35PM +0100, Simon Guinot wrote:
> >> The mvneta controller provides a 8-bit register to update the
> >> pending Tx descriptor counter. Then, a maximum of 255 Tx
> >> descriptors can be added at once. In the current code the
> >> mvneta_txq_pend_desc_add function assumes the caller takes care of
> >> this limit. But it is not the case. In some situations (xmit_more
> >> flag), more than 255 descriptors are added. When this happens, the
> >> Tx descriptor counter register is updated with a wrong value,
> >> which breaks the whole Tx queue management.
> >>
> >> This patch fixes the issue by allowing the mvneta_txq_pend_desc_add
> >> function to process more than 255 Tx descriptors.
> >>
> >> Fixes: 2a90f7e1d5d0 ("net: mvneta: add xmit_more support")
> >> Cc: sta...@vger.kernel.org # 4.11+
> >> Signed-off-by: Simon Guinot <simon.gui...@sequanux.org>
> >> ---
> >> drivers/net/ethernet/marvell/mvneta.c | 16 +++++++++-------
> >> 1 file changed, 9 insertions(+), 7 deletions(-)
> >>
> >> diff --git a/drivers/net/ethernet/marvell/mvneta.c
> >> b/drivers/net/ethernet/marvell/mvneta.c index
> >> 64a04975bcf8..027c08ce4e5d 100644 ---
> >> a/drivers/net/ethernet/marvell/mvneta.c +++
> >> b/drivers/net/ethernet/marvell/mvneta.c @@ -816,11 +816,14 @@
> >> static void mvneta_txq_pend_desc_add(struct mvneta_port *pp, {
> >> u32 val;
> >>
> >> - /* Only 255 descriptors can be added at once ; Assume
> >> caller
> >> - * process TX desriptors in quanta less than 256
> >> - */
> >> - val = pend_desc + txq->pending;
> >> - mvreg_write(pp, MVNETA_TXQ_UPDATE_REG(txq->id), val);
> >> + pend_desc += txq->pending;
> >> +
> >> + /* Only 255 Tx descriptors can be added at once */
> >> + while (pend_desc > 0) {
> >> + val = min(pend_desc, 255);
> >> + mvreg_write(pp, MVNETA_TXQ_UPDATE_REG(txq->id),
> >> val);
> >> + pend_desc -= val;
> >> + }
> >> txq->pending = 0;
> >> }
> >>
> >> @@ -2413,8 +2416,7 @@ static int mvneta_tx(struct sk_buff *skb,
> >> struct net_device *dev) if (txq->count >= txq->tx_stop_threshold)
> >> netif_tx_stop_queue(nq);
> >>
> >> - if (!skb->xmit_more || netif_xmit_stopped(nq) ||
> >> - txq->pending + frags >
> >> MVNETA_TXQ_DEC_SENT_MASK)
> >> + if (!skb->xmit_more || netif_xmit_stopped(nq))
> >> mvneta_txq_pend_desc_add(pp, txq, frags);
> >> else
> >> txq->pending += frags;
> >> --
> >> 2.9.3
