RE: [RFC/PATCH 13/18] ravb: Add rx_ring_free function support for GbEthernet

From: Biju Das <biju.das.jz@bp.renesas.com>
To: Sergey Shtylyov <s.shtylyov@omp.ru>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>
Cc: Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	Andrew Lunn <andrew@lunn.ch>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Adam Ford <aford173@gmail.com>,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
	"linux-renesas-soc@vger.kernel.org" 
	<linux-renesas-soc@vger.kernel.org>,
	Chris Paterson <Chris.Paterson2@renesas.com>,
	Biju Das <biju.das@bp.renesas.com>
Subject: RE: [RFC/PATCH 13/18] ravb: Add rx_ring_free function support for GbEthernet
Date: Tue, 28 Sep 2021 09:24:25 +0000	[thread overview]
Message-ID: <OS0PR01MB5922E75F05556EC526ABA3B686A89@OS0PR01MB5922.jpnprd01.prod.outlook.com> (raw)
In-Reply-To: <6d6c1a5d-fcaa-4af9-0ed8-51920c237bde@omp.ru>

Hi Sergei,

Thanks for the feedback.

> Subject: Re: [RFC/PATCH 13/18] ravb: Add rx_ring_free function support for
> GbEthernet
> 
> On 9/23/21 5:08 PM, Biju Das wrote:
> 
> > This patch adds rx_ring_free function support for GbEthernet found on
> > RZ/G2L SoC.
> >
> > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > ---
> >  drivers/net/ethernet/renesas/ravb_main.c | 22 +++++++++++++++++++++-
> >  1 file changed, 21 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/ethernet/renesas/ravb_main.c
> > b/drivers/net/ethernet/renesas/ravb_main.c
> > index 2c375002ebcb..038af36141bb 100644
> > --- a/drivers/net/ethernet/renesas/ravb_main.c
> > +++ b/drivers/net/ethernet/renesas/ravb_main.c
> > @@ -236,7 +236,27 @@ static int ravb_tx_free(struct net_device *ndev,
> > int q, bool free_txed_only)
> >
> >  static void ravb_rx_ring_free_rgeth(struct net_device *ndev, int q)
> > {
> > -	/* Place holder */
> > +	struct ravb_private *priv = netdev_priv(ndev);
> > +	unsigned int ring_size;
> > +	unsigned int i;
> > +
> > +	if (!priv->rgeth_rx_ring[q])
> 
>    Is the network control queue present on your hardware at all? Perhaps
> we can ignore q for now?

NC queue is not present on RZ/G2L. Will add a feature flag and function pointer related changes to
minimize the check for NC and avoid using NC queue for RZ/G2L platform.

Please let me know, if you think otherwise.

> 
> > +		return;
> > +
> > +	for (i = 0; i < priv->num_rx_ring[q]; i++) {
> > +		struct ravb_rx_desc *desc = &priv->rgeth_rx_ring[q][i];
> 
>    Looks like patch #12 should come after this one, not before...

Patch#12 is timestamp related and we agreed to merge with gPTP support case.

Regards,
Biju

> 
> > +
> > +		if (!dma_mapping_error(ndev->dev.parent,
> > +				       le32_to_cpu(desc->dptr)))
> > +			dma_unmap_single(ndev->dev.parent,
> > +					 le32_to_cpu(desc->dptr),
> > +					 RGETH_RX_BUFF_MAX,
> > +					 DMA_FROM_DEVICE);
> > +	}
> > +	ring_size = sizeof(struct ravb_rx_desc) * (priv->num_rx_ring[q] +
> 1);
> > +	dma_free_coherent(ndev->dev.parent, ring_size, priv-
> >rgeth_rx_ring[q],
> > +			  priv->rx_desc_dma[q]);
> > +	priv->rgeth_rx_ring[q] = NULL;
> >  }
> >
> >  static void ravb_rx_ring_free(struct net_device *ndev, int q)
> 
> MBR, Sergey