RE: [EXT] [PATCH net-next] net: enetc: add ethtool::get_channels support

[Wei Fang]

> -----Original Message-----
> From: Suman Ghosh <sumang@xxxxxxxxxxx>
> Sent: 2023年11月22日 18:50
> To: Wei Fang <wei.fang@xxxxxxx>; davem@xxxxxxxxxxxxx;
> edumazet@xxxxxxxxxx; kuba@xxxxxxxxxx; pabeni@xxxxxxxxxx; Claudiu
> Manoil <claudiu.manoil@xxxxxxx>; Vladimir Oltean
> <vladimir.oltean@xxxxxxx>; netdev@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Subject: RE: [EXT] [PATCH net-next] net: enetc: add ethtool::get_channels
> support
> 
> >Subject: [EXT] [PATCH net-next] net: enetc: add ethtool::get_channels
> >support
> >
> >External Email
> >
> >----------------------------------------------------------------------
> >Since ETHTOOL_MSG_RSS_GET netlink message [1] has been applied to
> >ethtool tree, there is a netlink error when using "ethtool -x eno0"
> >command to get RSS information from fsl-enetc driver, and the user
> >cannot get the information, the error logs are as follows:
> >
> >root@ls1028ardb:~# ./ethtool -x eno0
> >netlink error: Operation not supported
> >
> >The rationale is that ethtool will issue a ETHTOOL_MSG_CHANNELS_GET
> >netlink message to get the number of Rx ring. However, the fsl-enetc
> >driver doesn't support ethtool::get_channels, so it directly returns -
> >EOPNOTSUPP error.
> >
> >[1]:
> >https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Furlde
> >fense.proofpoint.com%2Fv2%2Furl%3Fu%3Dhttps-&data=05%7C01%7Cwei.f
> ang%40
> >nxp.com%7Ccb29522a88634f39882d08dbeb48c6b0%7C686ea1d3bc2b4c6fa
> 92cd99c5c
> >301635%7C0%7C0%7C638362470026457333%7CUnknown%7CTWFpbGZsb3
> d8eyJWIjoiMC4
> >wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%
> 7C%7C%7C
> >&sdata=j8g%2Filjj0mneiVEbRln1QpxFtBbudmQDfzqBqyfP9%2BY%3D&reserv
> ed=0
> >3A__git.kernel.org_pub_scm_linux_kernel_git_jkirsher_ethtool.git_commit
> >_
> >-3Fid-
> >3Dffab99c1f3820e21d65686e030dcf2c4fd0a8bd0&d=DwIDAg&c=nKjWec2b
> 6R0mOyPaz
> >7
> >xtfQ&r=7si3Xn9Ly-Se1a655kvEPIYU0nQ9HPeN280sEUv5ROU&m=-
> >6bW3FaCKau7jio6XSUWDZw3IEqdetIwhU_Bgcv87QcnjyMDGD0slJGQYFlbVx7
> l&s=8vMev
> >Y UEvNkyCjMDO278j67ir4daMquk6QK9wR65NSQ&e=
> >
> >Signed-off-by: Wei Fang <wei.fang@xxxxxxx>
> >---
> > .../net/ethernet/freescale/enetc/enetc_ethtool.c    | 13 +++++++++++++
> > 1 file changed, 13 insertions(+)
> >
> >diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
> >b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
> >index e993ed04ab57..5fa1000b9b83 100644
> >--- a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
> >+++ b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
> >@@ -740,6 +740,17 @@ static int enetc_set_rxfh(struct net_device *ndev,
> >const u32 *indir,
> > 	return err;
> > }
> >
> >+static void enetc_get_channels(struct net_device *ndev,
> >+			       struct ethtool_channels *ch) {
> >+	struct enetc_ndev_priv *priv = netdev_priv(ndev);
> >+
> >+	ch->max_rx = priv->num_rx_rings;
> >+	ch->max_tx = priv->num_tx_rings;
> >+	ch->rx_count = priv->num_rx_rings;
> >+	ch->tx_count = priv->num_tx_rings;
> [Suman] max_rx/tx and rx/tx_count can be different right? To me it seems like
> max_rx/tx should read the max value not the current configured values.

[Wei] Yes, but the current fsl-enetc driver doesn't support to dynamically configure the
number of tx/rx rings, so even we have more available rings than priv->num_rx_rings,
we can only the use priv->num_rx_rings rings. So I make the max_rx = rx_count.