Re: [PATCH net-next v3 4/4] net: phy: dp83td510: Add support for the DP83TD510 Ethernet PHY

[Dan Murphy]

Andrew

On 11/3/20 11:18 AM, Andrew Lunn wrote:
> On Tue, Nov 03, 2020 at 11:07:00AM -0600, Dan Murphy wrote:
> > Andrew
> >
> > On 10/30/20 3:15 PM, Andrew Lunn wrote:
> > > > +static int dp83td510_config_init(struct phy_device *phydev)
> > > > +{
> > > > +	struct dp83td510_private *dp83td510 = phydev->priv;
> > > > +	int mst_slave_cfg;
> > > > +	int ret = 0;
> > > > +
> > > > +	if (phy_interface_is_rgmii(phydev)) {
> > > > +		if (dp83td510->rgmii_delay) {
> > > > +			ret = phy_set_bits_mmd(phydev, DP83TD510_DEVADDR,
> > > > +					       DP83TD510_MAC_CFG_1, dp83td510->rgmii_delay);
> > > > +			if (ret)
> > > > +				return ret;
> > > > +		}
> > > > +	}
> > > Hi Dan
> > >
> > > I'm getting a bit paranoid about RGMII delays...
> > Not sure what this means.
> See the discussion and breakage around the realtek PHY. It wrongly
> implemented RGMII delays. When it was fixed, lots of board broke
> because the bug in the PHY driver hid bugs in the DT.
I will have to go find that thread. Do you have a link?
> > > Please don't use device_property_read_foo API, we don't want to give
> > > the impression it is O.K. to stuff DT properties in ACPI
> > > tables. Please use of_ API calls.
> > Hmm. Is this a new stance in DT handling for the networking tree?
> >
> > If it is should I go back and rework some of my other drivers that use
> > device_property APIs
> There is a slowly growing understanding what ACPI support in this area
> means. It seems to mean that the firmware should actually do all the
> setup, and the kernel should not touch the hardware configuration. But
> some developers are ignoring this, and just stuffing DT properties
> into ACPI tables and letting the kernel configure the hardware, if it
> happens to use the device_property_read API. So i want to make it
> clear that these properties are for device tree, and if you want to
> use ACPI, you should do things the ACPI way.
>
> For new code, i will be pushing for OF only calls. Older code is a bit
> more tricky. There might be boards out there using ACPI, but doing it
> wrongly, and stuffing OF properties into ACPI tables. We should try to
> avoid breaking them.

Got it.  I will move back to of_* calls

Dan


>        Andrew