Re: [dpdk-dev] [v1] net/i40e: fix RX/TX setup when restart port

["Yan, Zhirun" <zhirun.yan@intel.com>]

Hi Ilya,

> -----Original Message-----
> From: Ilya Maximets [mailto:i.maximets@samsung.com]
> Sent: Wednesday, November 28, 2018 5:32 PM
> To: Yan, Zhirun <zhirun.yan@intel.com>; dev@dpdk.org; Zhang, Qi Z
> <qi.z.zhang@intel.com>
> Cc: Wang, Haiyue <haiyue.wang@intel.com>
> Subject: Re: [v1] net/i40e: fix RX/TX setup when restart port
> 
> On 28.11.2018 19:51, Zhirun Yan wrote:
> > Before this patch, there are two functions that will clear RX/TX
> > queues
> > number: rte_eth_dev_close() and i40e_dev_free_queues(). But if also
> > i40e_dev_free_queues() clear it, RX/TX queues will not set up
> > correctly when restart port.
> 
> According to DPDK API device could not be restarted after rte_eth_dev_close:
> 
>   "Close a stopped Ethernet device. The device cannot be restarted!"
> 
> http://doc.dpdk.org/api/rte__ethdev_8h.html#a93eeb672a2f9cd18e338aad10
> c77687c
> 
> You should not close the device if you're willing to use it later.
> If you really want to close it, you'll need to detach it and attach back when
> needed.
> 

Thanks for your advice. I am agree with you.

By the way, I think the close will do some clean job in i40e. For example, the reset
function will call it in uninit  to release resource.

Rte_eth_dev_rx\tx_queue_config() malloc the dev->data->rx_queues, so
 dev->data->nb_rx_queues = 0 should be in rte layer when rte_eth_dev_close try to
release the queues.

I think I have write a bad commit, I will modify it in V2.


> >
> > Fixes: 6b4537128394 ("i40e: free queue memory when closing")
> >
> > Signed-off-by: Zhirun Yan <zhirun.yan@intel.com>
> > Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
> > ---
> >  drivers/net/i40e/i40e_rxtx.c | 2 --
> >  1 file changed, 2 deletions(-)
> >
> > diff --git a/drivers/net/i40e/i40e_rxtx.c
> > b/drivers/net/i40e/i40e_rxtx.c index e1152ff0e..cc953ad58 100644
> > --- a/drivers/net/i40e/i40e_rxtx.c
> > +++ b/drivers/net/i40e/i40e_rxtx.c
> > @@ -2753,7 +2753,6 @@ i40e_dev_free_queues(struct rte_eth_dev *dev)
> >  		i40e_dev_rx_queue_release(dev->data->rx_queues[i]);
> >  		dev->data->rx_queues[i] = NULL;
> >  	}
> > -	dev->data->nb_rx_queues = 0;
> >
> >  	for (i = 0; i < dev->data->nb_tx_queues; i++) {
> >  		if (!dev->data->tx_queues[i])
> > @@ -2761,7 +2760,6 @@ i40e_dev_free_queues(struct rte_eth_dev *dev)
> >  		i40e_dev_tx_queue_release(dev->data->tx_queues[i]);
> >  		dev->data->tx_queues[i] = NULL;
> >  	}
> > -	dev->data->nb_tx_queues = 0;
> >  }
> >
> >  #define I40E_FDIR_NUM_TX_DESC  I40E_MIN_RING_DESC
> >