Re: [PATCH v2 3/3] riscv: dts: thead: Add TH1520 ethernet nodes

From: Drew Fustini <dfustini@tenstorrent.com>
To: Andrew Lunn <andrew@lunn.ch>
Cc: "David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Alexandre Torgue <alexandre.torgue@foss.st.com>,
	Giuseppe Cavallaro <peppe.cavallaro@st.com>,
	Jose Abreu <joabreu@synopsys.com>,
	Jisheng Zhang <jszhang@kernel.org>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Emil Renner Berthing <emil.renner.berthing@canonical.com>,
	Drew Fustini <drew@pdp7.com>, Guo Ren <guoren@kernel.org>,
	Fu Wei <wefu@redhat.com>, Conor Dooley <conor@kernel.org>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	netdev@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-stm32@st-md-mailman.stormreply.com,
	linux-arm-kernel@lists.infradead.org,
	linux-riscv@lists.infradead.org
Subject: Re: [PATCH v2 3/3] riscv: dts: thead: Add TH1520 ethernet nodes
Date: Thu, 26 Sep 2024 12:13:06 -0700	[thread overview]
Message-ID: <ZvWyQo+2mwsC1HS6@x1> (raw)
In-Reply-To: <3e26f580-bc5d-448e-b5bd-9b607c33702b@lunn.ch>

On Thu, Sep 26, 2024 at 08:39:29PM +0200, Andrew Lunn wrote:
> > +&mdio0 {
> > +	phy0: ethernet-phy@1 {
> > +		reg = <1>;
> > +	};
> > +
> > +	phy1: ethernet-phy@2 {
> > +		reg = <2>;
> > +	};
> > +};
> 
> Two PHYs on one bus...

Thanks for pointing this out. I will move phy1 to mdio1.

> 
> > +		gmac1: ethernet@ffe7060000 {
> > +			compatible = "thead,th1520-gmac", "snps,dwmac-3.70a";
> > +			reg = <0xff 0xe7060000 0x0 0x2000>, <0xff 0xec004000 0x0 0x1000>;
> > +			reg-names = "dwmac", "apb";
> > +			interrupts = <67 IRQ_TYPE_LEVEL_HIGH>;
> > +			interrupt-names = "macirq";
> > +			clocks = <&clk CLK_GMAC_AXI>, <&clk CLK_GMAC_AXI>;
> > +			clock-names = "stmmaceth", "pclk";
> > +			snps,pbl = <32>;
> > +			snps,fixed-burst;
> > +			snps,multicast-filter-bins = <64>;
> > +			snps,perfect-filter-entries = <32>;
> > +			snps,axi-config = <&stmmac_axi_config>;
> > +			status = "disabled";
> > +
> > +			mdio1: mdio {
> > +				compatible = "snps,dwmac-mdio";
> > +				#address-cells = <1>;
> > +				#size-cells = <0>;
> > +			};
> > +		};
> > +
> > +		gmac0: ethernet@ffe7070000 {
> > +			compatible = "thead,th1520-gmac", "snps,dwmac-3.70a";
> > +			reg = <0xff 0xe7070000 0x0 0x2000>, <0xff 0xec003000 0x0 0x1000>;
> > +			reg-names = "dwmac", "apb";
> > +			interrupts = <66 IRQ_TYPE_LEVEL_HIGH>;
> > +			interrupt-names = "macirq";
> > +			clocks = <&clk CLK_GMAC_AXI>, <&clk CLK_GMAC_AXI>;
> 
> And the MACs are listed in opposite order. Does gmac1 probe first,
> find the PHY does not exist, and return -EPROBE_DEFER. Then gmac0
> probes successfully, and then sometime later gmac1 then reprobes?
> 
> I know it is normal to list nodes in address order, but you might be
> able to avoid the EPROBE_DEFER if you reverse the order.

The probe order seems to always be the ethernet@ffe7060000 (gmac1) first
and then ethernet@ffe7070000 (gmac0). I do not see any probe deferral
in the boot log [1].

Thanks,
Drew

[1] https://gist.github.com/pdp7/02a44b024bdb6be5fe61ac21303ab29a

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