RE: [PATCH 1/4] net: stmmac: update rx tail pointer register to fix rx dma hang issue.

From: biao huang
Date: Tue Apr 30 2019 - 04:56:13 EST


On Mon, 2019-04-29 at 08:51 +0000, Jose Abreu wrote:
> From: Biao Huang <biao.huang@xxxxxxxxxxxx>
> Date: Mon, Apr 29, 2019 at 07:15:53
>
> > Currently we will not update the receive descriptor tail pointer in
> > stmmac_rx_refill. Rx dma will think no available descriptors and stop
> > once received packets exceed DMA_RX_SIZE, so that the rx only test will fail.
> >
> > Update the receive tail pointer in stmmac_rx_refill to add more descriptors
> > to the rx channel, so packets can be received continually
> >
> > Signed-off-by: Biao Huang <biao.huang@xxxxxxxxxxxx>
> > ---
> > drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > index 97c5e1a..818ad88 100644
> > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> > @@ -3336,6 +3336,9 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv, u32 queue)
> > entry = STMMAC_GET_ENTRY(entry, DMA_RX_SIZE);
> > }
> > rx_q->dirty_rx = entry;
> > + stmmac_set_rx_tail_ptr(priv, priv->ioaddr,
> > + rx_q->dma_rx_phy + (entry * sizeof(struct dma_desc)),
>
> I think you can just use the "rx_q->rx_tail_addr" here. It'll always
> trigger a poll demand for the channel.
Yes, will use rx_q->rx_tail_addr here.
>
> Thanks,
> Jose Miguel Abreu