netdev - Re: [PATCH v1 2/2] net: emac: add support for device-tree based PHY discovery and setup

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Sun, 19 Feb 2017 21:13:02 -0800
From:   Florian Fainelli <f.fainelli@...il.com>
To:     Christian Lamparter <chunkeey@...glemail.com>,
        netdev@...r.kernel.org, devicetree@...r.kernel.org
Cc:     "David S . Miller" <davem@...emloft.net>,
        Ivan Mikhaylov <ivan@...ibm.com>, Andrew Lunn <andrew@...n.ch>,
        Rob Herring <robh+dt@...nel.org>
Subject: Re: [PATCH v1 2/2] net: emac: add support for device-tree based PHY
 discovery and setup



On 02/19/2017 01:22 PM, Christian Lamparter wrote:
> This patch adds glue-code that allows the EMAC driver to interface
> with the existing dt-supported PHYs in drivers/net/phy.
> 
> Because currently, the emac driver maintains a small library of
> supported phys for in a private phy.c file located in the drivers
> directory.
> 
> The support is limited to mostly single ethernet transceiver like the:
> CIS8201, BCM5248, ET1011C, Marvell 88E1111 and 88E1112, AR8035.
> 
> However, routers like the Netgear WNDR4700 and Cisco Meraki MX60(W)
> have a 5-port switch (AR8327N) attached to the EMAC. The switch chip
> is supported by the qca8k mdio driver, which uses the generic phy
> library. Another reason is that PHYLIB also supports the BCM54610,
> which was used for the Western Digital My Book Live.
> 
> This will now also make EMAC select PHYLIB.

This looks mostly good, except one thing below:

> 
> Signed-off-by: Christian Lamparter <chunkeey@...glemail.com>
> ---

> +static int emac_dt_phy_connect(struct emac_instance *dev,
> +			       struct device_node *phy_handle)
> +{
> +	u32 phy_flags = 0;
> +	int res;
> +
> +	res = of_property_read_u32(phy_handle, "phy-flags", &phy_flags);
> +	if (res < 0 && res != -EINVAL)
> +		return res;

phy-flags is not documented in the binding document, but looking at how
you pass it down, I don't think you should do this.

> +
> +	dev->phy.def = devm_kzalloc(&dev->ofdev->dev, sizeof(*dev->phy.def),
> +				    GFP_KERNEL);
> +	if (!dev->phy.def)
> +		return -ENOMEM;
> +
> +	dev->phy_dev = of_phy_connect(dev->ndev, phy_handle,
> +				      &emac_adjust_link, phy_flags,
> +				      dev->phy_mode);

phy_flags is meant to allow the MAC driver to pass information down to
the PHY driver, e.g: lane swap needed, a revision that could not be read
by the PHY itself, board-level workarounds etc.

> +	if (!dev->phy_dev) {
> +		dev_err(&dev->ofdev->dev, "failed to connect to PHY.\n");
> +		return -ENODEV;
> +	}
-- 
Florian