Re: [PATCH 5/8] net: ethernet: ti: am65-cpsw: Add support for fixed-link configuration

From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: Siddharth Vadapalli <s-vadapalli@ti.com>
Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
	pabeni@redhat.com, robh+dt@kernel.org,
	krzysztof.kozlowski@linaro.org,
	krzysztof.kozlowski+dt@linaro.org, vladimir.oltean@nxp.com,
	grygorii.strashko@ti.com, vigneshr@ti.com, nsekhar@ti.com,
	netdev@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, kishon@ti.com
Subject: Re: [PATCH 5/8] net: ethernet: ti: am65-cpsw: Add support for fixed-link configuration
Date: Wed, 14 Sep 2022 16:41:13 +0100	[thread overview]
Message-ID: <YyH2GcLCAN+9GAn8@shell.armlinux.org.uk> (raw)
In-Reply-To: <20220914095053.189851-6-s-vadapalli@ti.com>

On Wed, Sep 14, 2022 at 03:20:50PM +0530, Siddharth Vadapalli wrote:
> diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> index 72b1df12f320..1739c389af20 100644
> --- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> +++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> @@ -1494,10 +1494,50 @@ static void am65_cpsw_nuss_mac_config(struct phylink_config *config, unsigned in
>  							  phylink_config);
>  	struct am65_cpsw_port *port = container_of(slave, struct am65_cpsw_port, slave);
>  	struct am65_cpsw_common *common = port->common;
> +	struct fwnode_handle *fwnode;
> +	bool fixed_link = false;
>  
>  	if (common->pdata.extra_modes & BIT(state->interface))
>  		writel(AM65_CPSW_SGMII_CONTROL_MR_AN_ENABLE,
>  		       port->sgmii_base + AM65_CPSW_SGMII_CONTROL_REG);
> +
> +	/* Detecting fixed-link */
> +	fwnode = of_node_to_fwnode(port->slave.phy_node);
> +	if (fwnode)
> +		fixed_link = !!fwnode_get_named_child_node(fwnode, "fixed-link");
> +
> +	if (fixed_link) {
> +		/* In fixed-link mode, mac_link_up is not invoked.
> +		 * Therefore, the relevant mac_link_up operations
> +		 * have to be moved to mac_config.
> +		 */

This seems very wrong. Why is mac_link_up() not invoked? Have you
debugged this? It works for other people.

Please debug rather than adding hacks to drivers when you find
things that don't seem to work.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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