Hello Sergey,
> From: Sergey Shtylyov, Sent: Friday, December 1, 2023 5:55 PM
>
> On 12/1/23 8:46 AM, Yoshihiro Shimoda wrote:
>
> > If the driver would like to transmit a jumbo frame like 2KiB or more,
> > it should be split into multiple queues. In the near future, to support
> > this, add handling specific descriptor types F{START,MID,END}. However,
> > such jumbo frames will not happen yet because the maximum MTU size is
> > still default for now.
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> [...]
>
> > diff --git a/drivers/net/ethernet/renesas/rswitch.c b/drivers/net/ethernet/renesas/rswitch.c
> > index 009e6bfdad27..c5e3ee8f82bc 100644
> > --- a/drivers/net/ethernet/renesas/rswitch.c
> > +++ b/drivers/net/ethernet/renesas/rswitch.c
> > @@ -1631,15 +1631,44 @@ static bool rswitch_ext_desc_set(struct rswitch_device *rdev,
> [...]
> > static netdev_tx_t rswitch_start_xmit(struct sk_buff *skb, struct net_device *ndev)
> > {
> > struct rswitch_device *rdev = netdev_priv(ndev);
> > struct rswitch_gwca_queue *gq = rdev->tx_queue;
> > + dma_addr_t dma_addr, dma_addr_orig;
> > netdev_tx_t ret = NETDEV_TX_OK;
> > struct rswitch_ext_desc *desc;
> > - dma_addr_t dma_addr;
> > + unsigned int i, nr_desc;
> > + u8 die_dt;
> > + u16 len;
> >
> > - if (rswitch_get_num_cur_queues(gq) >= gq->ring_size - 1) {
> > + nr_desc = (skb->len - 1) / RSWITCH_DESC_BUF_SIZE + 1;
> > + if (rswitch_get_num_cur_queues(gq) >= gq->ring_size - nr_desc) {
> > netif_stop_subqueue(ndev, 0);
> > return NETDEV_TX_BUSY;
> > }
> > @@ -1647,19 +1676,26 @@ static netdev_tx_t rswitch_start_xmit(struct sk_buff *skb, struct net_device *nd
> > if (skb_put_padto(skb, ETH_ZLEN))
> > return ret;
> >
> > - dma_addr = dma_map_single(ndev->dev.parent, skb->data, skb->len, DMA_TO_DEVICE);
> > + dma_addr_orig = dma_map_single(ndev->dev.parent, skb->data, skb->len, DMA_TO_DEVICE);
> > if (dma_mapping_error(ndev->dev.parent, dma_addr))
>
> Not dma_addr_orig? dma_addr isn't even set at this point, no?
Oops. Thank you for your review! You're correct. I also realized the error path was wrong like below...
> dma_unmap_single(ndev->dev.parent, dma_addr, skb->len, DMA_TO_DEVICE);
I'll fix them on v3.
Best regards,
Yoshihiro Shimoda
>
> [...]
>
> MBR, Sergey
