Subject: Re: [RFC Patch net-next v1 9/9] r8169: add support for ethtool

From: Subbaraya Sundeep <[email-masked]>
Date: Sun, 26 Apr 2026 23:35:46 +0530

Hi,
On 2026-04-20 at 07:49:57, javen ([email-masked]) wrote:
> From: Javen Xu <[email-masked]>
> 
> This patch add support for changing rx queues by ethtool. We can set rx
> 1, 2, 4, 8 by ethtool -L eth1 rx num.
> 
> Signed-off-by: Javen Xu <[email-masked]>
> ---
>  drivers/net/ethernet/realtek/r8169_main.c | 68 +++++++++++++++++++++++
>  1 file changed, 68 insertions(+)
> 
> diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
> index 6b574fc336d6..57087abe7d88 100644
> --- a/drivers/net/ethernet/realtek/r8169_main.c
> +++ b/drivers/net/ethernet/realtek/r8169_main.c
> @@ -6518,6 +6518,72 @@ static void r8169_init_napi(struct rtl8169_private *tp)
>  	}
>  }
>  
> +static void rtl8169_get_channels(struct net_device *dev,
> +				 struct ethtool_channels *ch)
> +{
> +	struct rtl8169_private *tp = netdev_priv(dev);
> +
> +	ch->max_rx = tp->HwSuppNumRxQueues ? tp->HwSuppNumRxQueues : 1;
> +	ch->max_tx = tp->HwSuppNumTxQueues ? tp->HwSuppNumTxQueues : 1;
> +	ch->max_other = 0;
> +	ch->max_combined = 0;
> +
> +	ch->rx_count = tp->num_rx_rings;
> +	ch->tx_count = tp->num_tx_rings;
> +	ch->other_count = 0;
> +	ch->combined_count = 0;
> +}
> +
> +static int rtl8169_set_channels(struct net_device *dev,
> +				struct ethtool_channels *ch)
> +{
> +	struct rtl8169_private *tp = netdev_priv(dev);
> +	bool if_running = netif_running(dev);
> +	int i;
> +
> +	if (!tp->rss_support && (ch->rx_count > 1 || ch->tx_count > 1)) {
> +		netdev_warn(dev, "This chip does not support multiple channels/RSS.\n");
> +		return -EOPNOTSUPP;
> +	}
> +
> +	if (ch->rx_count == 0 || ch->tx_count == 0)
> +		return -EINVAL;
> +	if (ch->rx_count > tp->HwSuppNumRxQueues ||
> +	    ch->tx_count > tp->HwSuppNumTxQueues)
> +		return -EINVAL;
> +	if (ch->other_count || ch->combined_count)
> +		return -EINVAL;
> +
> +	if (ch->rx_count == tp->num_rx_rings &&
> +	    ch->tx_count == tp->num_tx_rings)
> +		return 0;
> +
Revisit the above checks, they are not needed since ethtool code does all these.
> +	if (if_running)
> +		rtl8169_close(dev);
> +
> +	tp->num_rx_rings = ch->rx_count;
> +	tp->num_tx_rings = ch->tx_count;
> +
> +	tp->rss_enable = (tp->num_rx_rings > 1 && tp->rss_support);
Please help me understand your HW..Is there a condition where there are
multi Rx queues but HW do not support RSS? I dont know how traffic is distributed
across queues in that case (maybe - pinning flows to individual queues via
ntuple or TC ?)

Thanks,
Sundeep

> +
> +	for (i = 0; i < tp->HwSuppIndirTblEntries; i++) {
> +		if (tp->rss_enable)
> +			tp->rss_indir_tbl[i] = ethtool_rxfh_indir_default(i, tp->num_rx_rings);
> +		else
> +			tp->rss_indir_tbl[i] = 0;
> +	}
> +
> +	if (tp->rss_enable)
> +		tp->InitRxDescType = RX_DESC_RING_TYPE_RSS;
> +	else
> +		tp->InitRxDescType = RX_DESC_RING_TYPE_DEAFULT;
> +
> +	if (if_running)
> +		return rtl_open(dev);
> +
> +	return 0;
> +}
> +
>  static const struct ethtool_ops rtl8169_ethtool_ops = {
>  	.supported_coalesce_params = ETHTOOL_COALESCE_USECS |
>  				     ETHTOOL_COALESCE_MAX_FRAMES,
> @@ -6536,6 +6602,8 @@ static const struct ethtool_ops rtl8169_ethtool_ops = {
>  	.nway_reset		= phy_ethtool_nway_reset,
>  	.get_eee		= rtl8169_get_eee,
>  	.set_eee		= rtl8169_set_eee,
> +	.get_channels		= rtl8169_get_channels,
> +	.set_channels		= rtl8169_set_channels,
>  	.get_link_ksettings	= phy_ethtool_get_link_ksettings,
>  	.set_link_ksettings	= rtl8169_set_link_ksettings,
>  	.get_ringparam		= rtl8169_get_ringparam,
> -- 
> 2.43.0
>