netdev - Re: [PATCH net-next v3 3/6] net: hisilicon: add support for hisi

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Message-ID: <20240220154737.705c33e5@device-28.home>
Date: Tue, 20 Feb 2024 15:47:37 +0100
From: Maxime Chevallier <maxime.chevallier@...tlin.com>
To: Yang Xiwen via B4 Relay <devnull+forbidden405.outlook.com@...nel.org>
Cc: <forbidden405@...look.com>, Yisen Zhuang <yisen.zhuang@...wei.com>,
 Salil Mehta <salil.mehta@...wei.com>, "David S. Miller"
 <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski
 <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, Rob Herring
 <robh+dt@...nel.org>, Krzysztof Kozlowski
 <krzysztof.kozlowski+dt@...aro.org>, Conor Dooley <conor+dt@...nel.org>,
 Andrew Lunn <andrew@...n.ch>, Heiner Kallweit <hkallweit1@...il.com>,
 Russell King <linux@...linux.org.uk>, netdev@...r.kernel.org,
 linux-kernel@...r.kernel.org, devicetree@...r.kernel.org, Simon Horman
 <horms@...nel.org>
Subject: Re: [PATCH net-next v3 3/6] net: hisilicon: add support for
 hisi_femac core on Hi3798MV200

Hello,

On Tue, 20 Feb 2024 03:57:38 +0800
Yang Xiwen via B4 Relay <devnull+forbidden405.outlook.com@...nel.org>
wrote:

> From: Yang Xiwen <forbidden405@...look.com>
> 
> Register the sub MDIO bus if it is found. Also implement the internal
> PHY reset procedure as needed.
> 
> Note it's unable to put the MDIO bus node outside of MAC controller
> (i.e. at the same level in the parent bus node). Because we need to
> control all clocks and resets in FEMAC driver due to the phy reset
> procedure. So the clocks can't be assigned to MDIO bus device, which is
> an essential resource for the MDIO bus to work.
> 
> No backward compatibility is maintained since the only existing
> user(Hi3516DV300) has not received any updates from HiSilicon for about
> 8 years already. And till today, no mainline dts for this SoC is found.
> It seems unlikely that there are still existing mainline Hi3516DV300
> users. The effort to maintain the old binding seems gain a little.
> 
> Signed-off-by: Yang Xiwen <forbidden405@...look.com>

Besides what Andrew and Simon already mentionned, I have a few other
small comments :

[...]

> @@ -797,23 +816,22 @@ static int hisi_femac_drv_probe(struct platform_device *pdev)
>  		goto out_free_netdev;
>  	}
>  
> -	priv->clk = devm_clk_get(&pdev->dev, NULL);
> -	if (IS_ERR(priv->clk)) {
> -		dev_err(dev, "failed to get clk\n");
> -		ret = -ENODEV;
> +	ret = devm_clk_bulk_get_all(&pdev->dev, &priv->clks);
> +	if (ret < 0 || ret != CLK_NUM) {
> +		dev_err(dev, "failed to get clk bulk: %d\n", ret);
>  		goto out_free_netdev;
>  	}
>  
> -	ret = clk_prepare_enable(priv->clk);
> +	ret = clk_bulk_prepare_enable(CLK_NUM, priv->clks);
>  	if (ret) {
> -		dev_err(dev, "failed to enable clk %d\n", ret);
> +		dev_err(dev, "failed to enable clk bulk: %d\n", ret);
>  		goto out_free_netdev;
>  	}
>  
>  	priv->mac_rst = devm_reset_control_get(dev, "mac");
>  	if (IS_ERR(priv->mac_rst)) {
>  		ret = PTR_ERR(priv->mac_rst);
> -		goto out_disable_clk;
> +		goto out_free_netdev;

When you return here (or even later), you are missing a call to
"clk_bulk_disable_unprepare" in the cleanup path

>  	}
>  	hisi_femac_core_reset(priv);
>  
> @@ -826,15 +844,34 @@ static int hisi_femac_drv_probe(struct platform_device *pdev)
>  						 priv->phy_reset_delays,
>  						 DELAYS_NUM);
>  		if (ret)
> -			goto out_disable_clk;
> +			goto out_free_netdev;
>  		hisi_femac_phy_reset(priv);
>  	}
>  
> +	// Register the optional MDIO bus

I think this comment style should be avoided, in favor of C-style
comments ( /* blabla */ )

> +	for_each_available_child_of_node(node, mdio_np) {
> +		if (of_node_name_prefix(mdio_np, "mdio")) {
> +			priv->mdio_pdev = of_platform_device_create(mdio_np, NULL, dev);
> +			of_node_put(mdio_np);
> +			if (!priv->mdio_pdev) {
> +				dev_err(dev, "failed to register MDIO bus device\n");
> +				ret = -ENODEV;
> +				goto out_free_netdev;
> +			}
> +			mdio_registered = true;
> +			break;
> +		}
> +		of_node_put(mdio_np);
> +	}
> +
> +	if (!mdio_registered)
> +		dev_warn(dev, "MDIO subnode not found. This is usually a bug.\n");
> +
>  	phy = of_phy_get_and_connect(ndev, node, hisi_femac_adjust_link);
>  	if (!phy) {
>  		dev_err(dev, "connect to PHY failed!\n");
>  		ret = -ENODEV;
> -		goto out_disable_clk;
> +		goto out_unregister_mdio_bus;
>  	}
>  
>  	phy_attached_print(phy, "phy_id=0x%.8lx, phy_mode=%s\n",

Thanks,

Maxime