Re: [PATCH v8 net-next 09/11] net: ethernet: ti: am65-cpsw-qos: Add Frame Preemption MAC Merge support

[Vladimir Oltean]

On Wed, Dec 13, 2023 at 01:07:19PM +0200, Roger Quadros wrote:
> - Fix am65_cpsw_iet_get_verify_timeout_ms() to default to timeout for
>   1G link if link is inactive.
> +
> +static int am65_cpsw_set_mm(struct net_device *ndev, struct ethtool_mm_cfg *cfg,
> +			    struct netlink_ext_ack *extack)
> +{
> +	val = readl(port->port_base + AM65_CPSW_PN_REG_IET_CTRL);
> +	if (cfg->verify_enabled) {
> +		val &= ~AM65_CPSW_PN_IET_MAC_DISABLEVERIFY;
> +		/* Reset Verify state machine. Verification won't start here.
> +		 * Verification will be done once link-up.
> +		 */
> +		val |= AM65_CPSW_PN_IET_MAC_LINKFAIL;
> +	} else {
> +		val |= AM65_CPSW_PN_IET_MAC_DISABLEVERIFY;
> +		/* Clear LINKFAIL to allow verify/response packets */
> +		val &= ~AM65_CPSW_PN_IET_MAC_LINKFAIL;
> +	}
> +
> +	val &= ~AM65_CPSW_PN_IET_MAC_MAC_ADDFRAGSIZE_MASK;
> +	val |= AM65_CPSW_PN_IET_MAC_SET_ADDFRAGSIZE(add_frag_size);
> +	writel(val, port->port_base + AM65_CPSW_PN_REG_IET_CTRL);
> +
> +	/* verify_timeout_count can only be set at valid link */
> +	if (cfg->verify_time > 0)
> +		port->qos.iet.verify_time_ms = cfg->verify_time;
> +	else
> +		port->qos.iet.verify_time_ms = 10;

I don't think I understand what the check is for? The netlink policy for
ETHTOOL_A_MM_VERIFY_TIME limits the range between 1 ms and 128 ms.
How can it be 0?

> +
> +	/* enable/disable preemption based on link status */
> +	am65_cpsw_iet_commit_preemptible_tcs(port);
> +
> +	return 0;
> +}