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SubjectRe: [RFC PATCH 2/3] net: sparx5: Add Sparx5 switchdev driver
> +/* Add a potentially wrapping 32 bit value to a 64 bit counter */
> +static inline void sparx5_update_counter(u64 *cnt, u32 val)
> +{
> + if (val < (*cnt & U32_MAX))
> + *cnt += (u64)1 << 32; /* value has wrapped */
> +
> + *cnt = (*cnt & ~(u64)U32_MAX) + val;
> +}

I don't follow what this is doing. Could you give some examples?

> +static const char *const sparx5_stats_layout[] = {
> + "rx_in_bytes",
> + "rx_symbol_err",
> + "rx_pause",
> + "rx_unsup_opcode",

> +static void sparx5_update_port_stats(struct sparx5 *sparx5, int portno)
> +{
> + struct sparx5_port *spx5_port = sparx5->ports[portno];
> + bool high_speed_dev = sparx5_is_high_speed_device(&spx5_port->conf);

Reverse christmas tree. Which in this case, means you need to move the
assignment into the body of the code.

> +static void sparx5_get_sset_strings(struct net_device *ndev, u32 sset, u8 *data)
> +{
> + struct sparx5_port *port = netdev_priv(ndev);
> + struct sparx5 *sparx5 = port->sparx5;
> + int idx;
> +
> + if (sset != ETH_SS_STATS)
> + return;
> +
> + for (idx = 0; idx < sparx5->num_stats; idx++)
> + memcpy(data + idx * ETH_GSTRING_LEN,
> + sparx5->stats_layout[idx], ETH_GSTRING_LEN);

You cannot use memcpy here, because the strings you have defined are
not ETH_GSTRING_LEN long. We once had a driver which happened to have
its strings at the end of a page. The memcpy would copy the string,
but keep going passed the end of string, over the page boundary, and
trigger a segmentation fault.

Andrew

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