Re: [PATCH RFC mlx5-next 0/1] net/mlx5e: Expose physical received bits counters to ethtool

[Tariq Toukan]

On 13/01/2026 8:31, Tariq Toukan wrote:
> On 12/01/2026 9:03, Kenta Akagi wrote:
> > Hi,
> >
> > I would like to measure the cable BER on ConnectX.
> >
> > According to the documentation[1][2], there are counters that can be used
> > for this purpose: rx_corrected_bits_phy, rx_pcs_symbol_err_phy and
> > rx_bits_phy. However, rx_bits_phy does not show up in ethtool
> > statistics.
> >
> > This patch exposes the PPCNT phy_received_bits as rx_bits_phy.
> >
> >
> > On a ConnectX-5 with 25Gbase connection, it works as expected.
> >
> > On the other hand, although I have not verified it, in an 800Gbps
> > environment rx_bits_phy would likely overflow after about 124 days.
> > Since I cannot judge whether this is acceptable, I am posting this as an
> > RFC first.
>
> Hi,
>
> This is a 64-bits counter so no overflow is expected.

Sorry, ignore my comment, your numbers make sense.
Maybe it's ~248 days, but same idea.

> > [1] commit 8ce3b586faa4 ("net/mlx5: Add counter information to mlx5
> >      driver documentation")
> > [2] https://docs.kernel.org/networking/device_drivers/ethernet/ 
> > mellanox/mlx5/counters.html
> >
> > Kenta Akagi (1):
> >    net/mlx5e: Expose physical received bits counters to ethtool
> >
> >   drivers/net/ethernet/mellanox/mlx5/core/en_stats.c | 1 +
> >   1 file changed, 1 insertion(+)