Re: [PATCH net-next 06/15] net: sgi: ioc3-eth: get rid of ioc3_clean_rx_ring()

From: Jakub Kicinski
Date: Wed Aug 28 2019 - 19:03:12 EST


On Wed, 28 Aug 2019 16:03:05 +0200, Thomas Bogendoerfer wrote:
> Clean rx ring is just called once after a new ring is allocated, which
> is per definition clean. So there is not need for this function.
>
> Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@xxxxxxx>
> ---
> drivers/net/ethernet/sgi/ioc3-eth.c | 21 ---------------------
> 1 file changed, 21 deletions(-)
>
> diff --git a/drivers/net/ethernet/sgi/ioc3-eth.c b/drivers/net/ethernet/sgi/ioc3-eth.c
> index 6ca560d4ab79..39631e067b71 100644
> --- a/drivers/net/ethernet/sgi/ioc3-eth.c
> +++ b/drivers/net/ethernet/sgi/ioc3-eth.c
> @@ -761,26 +761,6 @@ static void ioc3_mii_start(struct ioc3_private *ip)
> add_timer(&ip->ioc3_timer);
> }
>
> -static inline void ioc3_clean_rx_ring(struct ioc3_private *ip)
> -{
> - struct ioc3_erxbuf *rxb;
> - struct sk_buff *skb;
> - int i;
> -
> - for (i = ip->rx_ci; i & 15; i++) {
> - ip->rx_skbs[ip->rx_pi] = ip->rx_skbs[ip->rx_ci];
> - ip->rxr[ip->rx_pi++] = ip->rxr[ip->rx_ci++];
> - }
> - ip->rx_pi &= RX_RING_MASK;
> - ip->rx_ci &= RX_RING_MASK;
> -
> - for (i = ip->rx_ci; i != ip->rx_pi; i = (i + 1) & RX_RING_MASK) {
> - skb = ip->rx_skbs[i];
> - rxb = (struct ioc3_erxbuf *)(skb->data - RX_OFFSET);
> - rxb->w0 = 0;

There's gotta be some purpose to setting this w0 word to zero no?
ioc3_rx() uses that to see if the descriptor is done, and dutifully
clears it after..

> - }
> -}
> -
> static inline void ioc3_clean_tx_ring(struct ioc3_private *ip)
> {
> struct sk_buff *skb;
> @@ -860,7 +840,6 @@ static void ioc3_init_rings(struct net_device *dev)
> ioc3_free_rings(ip);
> ioc3_alloc_rings(dev);
>
> - ioc3_clean_rx_ring(ip);
> ioc3_clean_tx_ring(ip);
>
> /* Now the rx ring base, consume & produce registers. */