RE: [PATCH net-next 09/18] ravb: Factorise ravb_ring_free function

[Biju Das <biju.das.jz@bp.renesas.com>]

Hi Sergei,


> Subject: RE: [PATCH net-next 09/18] ravb: Factorise ravb_ring_free
> function
> 
> Hi Sergei,
> 
> Thanks for the feedback.
> 
> > Subject: Re: [PATCH net-next 09/18] ravb: Factorise ravb_ring_free
> > function
> >
> > Hello!
> >
> > On 7/22/21 5:13 PM, Biju Das wrote:
> >
> > > Extended descriptor support in RX is available for R-Car where as it
> > > is a normal descriptor for RZ/G2L. Factorise ravb_ring_free function
> > > so that it can support later SoC.
> > >
> > > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > > Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > ---
> > >  drivers/net/ethernet/renesas/ravb.h      |  5 +++
> > >  drivers/net/ethernet/renesas/ravb_main.c | 49
> > > ++++++++++++++++--------
> > >  2 files changed, 37 insertions(+), 17 deletions(-)
> > >
> > > diff --git a/drivers/net/ethernet/renesas/ravb.h
> > > b/drivers/net/ethernet/renesas/ravb.h
> > > index a474ed68db22..3a9cf6e8671a 100644
> > > --- a/drivers/net/ethernet/renesas/ravb.h
> > > +++ b/drivers/net/ethernet/renesas/ravb.h
> > > @@ -988,7 +988,12 @@ enum ravb_chip_id {
> > >  	RCAR_GEN3,
> > >  };
> > >
> > > +struct ravb_ops {
> > > +	void (*ring_free)(struct net_device *ndev, int q);
> >
> >    Hmm, why not store it right in the *struct* ravb_drv_data?
> 
> OK.
> 
> >
> > > +};
> > > +
> > >  struct ravb_drv_data {
> > > +	const struct ravb_ops *ravb_ops;
> > >  	netdev_features_t net_features;
> > >  	netdev_features_t net_hw_features;
> > >  	const char (*gstrings_stats)[ETH_GSTRING_LEN];
> > > diff --git a/drivers/net/ethernet/renesas/ravb_main.c
> > > b/drivers/net/ethernet/renesas/ravb_main.c
> > > index 4ef2565534d2..a3b8b243fd54 100644
> > > --- a/drivers/net/ethernet/renesas/ravb_main.c
> > > +++ b/drivers/net/ethernet/renesas/ravb_main.c
> > > @@ -247,30 +247,39 @@ static int ravb_tx_free(struct net_device
> > > *ndev, int q, bool free_txed_only)  }
> > >
> > >  /* Free skb's and DMA buffers for Ethernet AVB */ -static void
> > > ravb_ring_free(struct net_device *ndev, int q)
> > > +static void ravb_ring_free_rx(struct net_device *ndev, int q)
> >
> >    How about ravb_rx_ring_free() instead?
> Agreed.
> 
> >
> > >  {
> > >  	struct ravb_private *priv = netdev_priv(ndev);
> > > -	int num_tx_desc = priv->num_tx_desc;
> > >  	int ring_size;
> > >  	int i;
> > >
> > > -	if (priv->rx_ring[q]) {
> > > -		for (i = 0; i < priv->num_rx_ring[q]; i++) {
> > > -			struct ravb_ex_rx_desc *desc = &priv->rx_ring[q][i];
> > > +	for (i = 0; i < priv->num_rx_ring[q]; i++) {
> > > +		struct ravb_ex_rx_desc *desc = &priv->rx_ring[q][i];
> > >
> > > -			if (!dma_mapping_error(ndev->dev.parent,
> > > -					       le32_to_cpu(desc->dptr)))
> > > -				dma_unmap_single(ndev->dev.parent,
> > > -						 le32_to_cpu(desc->dptr),
> > > -						 RX_BUF_SZ,
> > > -						 DMA_FROM_DEVICE);
> > > -		}
> > > -		ring_size = sizeof(struct ravb_ex_rx_desc) *
> > > -			    (priv->num_rx_ring[q] + 1);
> > > -		dma_free_coherent(ndev->dev.parent, ring_size, priv-
> > >rx_ring[q],
> > > -				  priv->rx_desc_dma[q]);
> > > -		priv->rx_ring[q] = NULL;
> > > +		if (!dma_mapping_error(ndev->dev.parent,
> > > +				       le32_to_cpu(desc->dptr)))
> > > +			dma_unmap_single(ndev->dev.parent,
> > > +					 le32_to_cpu(desc->dptr),
> > > +					 RX_BUF_SZ,
> > > +					 DMA_FROM_DEVICE);
> > >  	}
> > > +	ring_size = sizeof(struct ravb_ex_rx_desc) *
> > > +		    (priv->num_rx_ring[q] + 1);
> > > +	dma_free_coherent(ndev->dev.parent, ring_size, priv->rx_ring[q],
> > > +			  priv->rx_desc_dma[q]);
> > > +	priv->rx_ring[q] = NULL;
> >
> >    Couldn't this be moved into the new ravb_ring_free(), like the
> > initial NULL check?
> 
> For RZ/G2L, it is priv->rgeth_rx_ring, that is the reason.
> 
> I can move the initial NULL check here, so the generic ravb_ring_free does
> not differentiate between
> priv->rx_ring and priv->rgeth_rx_ring. See below.
> 
> >
> > > +}
> > > +
> > > +static void ravb_ring_free(struct net_device *ndev, int q) {
> > > +	struct ravb_private *priv = netdev_priv(ndev);
> > > +	const struct ravb_drv_data *info = priv->info;
> > > +	int num_tx_desc = priv->num_tx_desc;
> > > +	int ring_size;
> > > +	int i;
> > > +
> > > +	if (priv->rx_ring[q])
> > > +		info->ravb_ops->ring_free(ndev, q);
> >
> >    ... here?
> 
>      It will be just  info->ravb_ops->ring_free(ndev, q); And NULL check
> will be handled respective rx helper function.

I will be sending next set of patches incorporating the above comments
within couple of days.

Regards,
Biju