Re: [PATCH net-next 2/2] net: macb: Add zynqmp SGMII dynamic configuration support

[Andrew Lunn <andrew@lunn.ch>]

On Mon, Jul 25, 2022 at 02:34:51PM +0000, Pandey, Radhey Shyam wrote:
> > -----Original Message-----
> > From: Andrew Lunn <andrew@lunn.ch>
> > Sent: Sunday, July 24, 2022 10:24 PM
> > To: Pandey, Radhey Shyam <radhey.shyam.pandey@amd.com>
> > Cc: michal.simek@xilinx.com; nicolas.ferre@microchip.com;
> > claudiu.beznea@microchip.com; davem@davemloft.net;
> > edumazet@google.com; kuba@kernel.org; pabeni@redhat.com;
> > gregkh@linuxfoundation.org; ronak.jain@xilinx.com; linux-arm-
> > kernel@lists.infradead.org; linux-kernel@vger.kernel.org;
> > netdev@vger.kernel.org; git@xilinx.com; git (AMD-Xilinx) <git@amd.com>
> > Subject: Re: [PATCH net-next 2/2] net: macb: Add zynqmp SGMII dynamic
> > configuration support
> > 
> > > +		ret = of_property_read_u32_array(pdev->dev.of_node,
> > "power-domains",
> > > +						 pm_info,
> > ARRAY_SIZE(pm_info));
> > > +		if (ret < 0) {
> > > +			dev_err(&pdev->dev, "Failed to read power
> > management information\n");
> > > +			return ret;
> > > +		}
> > > +		ret = zynqmp_pm_set_gem_config(pm_info[1],
> > GEM_CONFIG_FIXED, 0);
> > > +		if (ret < 0)
> > > +			return ret;
> > > +
> > 
> > Documentation/devicetree/bindings/net/cdns,macb.yaml says:
> > 
> >   power-domains:
> >     maxItems: 1
> > 
> > Yet you are using pm_info[1]?
> 
> >From power-domain description - It's a phandle and PM domain 
> specifier as defined by bindings of the power controller specified
> by phandle.
> 
> I assume the numbers of cells is specified by "#power-domain-cells":
> Power-domain-cell is set to 1 in this case.
> 
> arch/arm64/boot/dts/xilinx/zynqmp.dtsi
> #power-domain-cells = <1>;
> power-domains = <&zynqmp_firmware PD_ETH_0>;
> 
> Please let me know your thoughts.

Ah, so you ignore the phandle value, and just use the PD_ETH_0?

How robust is this? What if somebody specified a different power
domain?

	Andrew