Re: [PATCH net-next 3/3] net: stmmac: Add glue layer for Spacemit K3 SoC

From: "Russell King (Oracle)" <linux@armlinux.org.uk>
To: Inochi Amaoto <inochiama@gmail.com>
Cc: Andrew Lunn <andrew+netdev@lunn.ch>,
	"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>, Yixun Lan <dlan@gentoo.org>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>,
	Alexandre Torgue <alexandre.torgue@foss.st.com>,
	Richard Cochran <richardcochran@gmail.com>,
	Paul Walmsley <pjw@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Alexandre Ghiti <alex@ghiti.fr>,
	Yanteng Si <siyanteng@cqsoftware.com.cn>,
	Yao Zi <ziyao@disroot.org>,
	Vladimir Oltean <vladimir.oltean@nxp.com>,
	Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	Choong Yong Liang <yong.liang.choong@linux.intel.com>,
	Maxime Chevallier <maxime.chevallier@bootlin.com>,
	Chen-Yu Tsai <wens@kernel.org>,
	Shangjuan Wei <weishangjuan@eswincomputing.com>,
	Boon Khai Ng <boon.khai.ng@altera.com>,
	Quentin Schulz <quentin.schulz@cherry.de>,
	Giuseppe Cavallaro <peppe.cavallaro@st.com>,
	Jose Abreu <joabreu@synopsys.com>,
	netdev@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org,
	spacemit@lists.linux.dev,
	linux-stm32@st-md-mailman.stormreply.com,
	linux-arm-kernel@lists.infradead.org,
	Longbin Li <looong.bin@gmail.com>
Subject: Re: [PATCH net-next 3/3] net: stmmac: Add glue layer for Spacemit K3 SoC
Date: Wed, 21 Jan 2026 12:03:36 +0000	[thread overview]
Message-ID: <aXDAmDEpUArE1_en@shell.armlinux.org.uk> (raw)
In-Reply-To: <aW8MJpERR3TmsiKg@inochi.infowork>

On Tue, Jan 20, 2026 at 01:05:39PM +0800, Inochi Amaoto wrote:
> > > +	mask = RGMII_RX_DLINE_STEP | RGMII_TX_DLINE_CODE | RGMII_TX_DLINE_EN |
> > > +	       RGMII_TX_DLINE_STEP | RGMII_RX_DLINE_CODE | RGMII_RX_DLINE_EN;
> > > +	val = FIELD_PREP(RGMII_TX_DLINE_CODE, tx_config) |
> > > +	      FIELD_PREP(RGMII_TX_DLINE_CODE, tx_code) | RGMII_TX_DLINE_EN |
> > > +	      FIELD_PREP(RGMII_TX_DLINE_CODE, rx_config) |
> > > +	      FIELD_PREP(RGMII_RX_DLINE_CODE, rx_code) | RGMII_RX_DLINE_EN;
> > 
> > These FIELD_PREP() fields look wrong. Did you mean to use DLINE_CODE
> > both tx_config and tx_code, and did you mean to use TX_DLINE_CODE for
> > rx_config ?
> > 
> 
> This should be RGMII_TX_DLINE_CODE. This is a copy paste error, I
> will fix it.

Are you sure?

In that case, please change this to:

	val = FIELD_PREP(RGMII_TX_DLINE_CODE, tx_config | tx_code |
					      rx_config | rx_code) |
	      RGMII_TX_DLINE_EN | RGMII_RX_DLINE_EN;

If that isn't what you meant, then your reply is wrong, and it seems
you're confused, which makes me then question how reliable your
replies are.

> > > +	plat_dat->clk_tx_i = devm_clk_get_enabled(&pdev->dev, "tx");
> > > +	if (IS_ERR(plat_dat->clk_tx_i))
> > > +		return dev_err_probe(&pdev->dev, PTR_ERR(plat_dat->clk_tx_i),
> > > +				     "failed to get tx clock\n");
> > 
> > You set plat_dat->clk_tx_i, but you don't point
> > plat_dat->set_clk_tx_rate at anything, which means the stmmac core
> > does nothing with this.
> > 
> 
> Yes, the vendor told me that the internal tx clock rate will be auto
> changed when the speed rate is changed. So no software interaction
> is needed.

Please do not assign a clock to clk_tx_i that is not the dwmac
clk_tx_i input. clk_tx_i is a name used by the Synopsys DWMAC for a
specific clock.

As you don't need to do anything with it other than to get and enable
it, consider using just a local variable here.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!