Re: [PATCH 1/3] net: ethernet: stmmac: dwmac-rk: Disable delayline if it is invalid

From: Andrew Lunn <andrew@lunn.ch>
To: Sebastian Reichel <sebastian.reichel@collabora.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>,
	Alexandre Torgue <alexandre.torgue@foss.st.com>,
	Jose Abreu <joabreu@synopsys.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	netdev@vger.kernel.org, linux-rockchip@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
	David Wu <david.wu@rock-chips.com>,
	kernel@collabora.com
Subject: Re: [PATCH 1/3] net: ethernet: stmmac: dwmac-rk: Disable delayline if it is invalid
Date: Fri, 24 Jun 2022 13:18:53 +0200	[thread overview]
Message-ID: <YrWdnQKVbJR+NrfH@lunn.ch> (raw)
In-Reply-To: <20220623162850.245608-2-sebastian.reichel@collabora.com>

> @@ -1422,7 +1420,7 @@ static struct rk_priv_data *rk_gmac_setup(struct platform_device *pdev,
>  
>  	ret = of_property_read_u32(dev->of_node, "tx_delay", &value);
>  	if (ret) {
> -		bsp_priv->tx_delay = 0x30;
> +		bsp_priv->tx_delay = -1;
>  		dev_err(dev, "Can not read property: tx_delay.");
>  		dev_err(dev, "set tx_delay to 0x%x\n",
>  			bsp_priv->tx_delay);
> @@ -1433,7 +1431,7 @@ static struct rk_priv_data *rk_gmac_setup(struct platform_device *pdev,
>  
>  	ret = of_property_read_u32(dev->of_node, "rx_delay", &value);
>  	if (ret) {
> -		bsp_priv->rx_delay = 0x10;
> +		bsp_priv->rx_delay = -1;
>  		dev_err(dev, "Can not read property: rx_delay.");
>  		dev_err(dev, "set rx_delay to 0x%x\n",
>  			bsp_priv->rx_delay);

rockchip-dwmac.yaml says:

  tx_delay:
    description: Delay value for TXD timing. Range value is 0~0x7F, 0x30 as default.
    $ref: /schemas/types.yaml#/definitions/uint32

  rx_delay:
    description: Delay value for RXD timing. Range value is 0~0x7F, 0x10 as default.
    $ref: /schemas/types.yaml#/definitions/uint32

So it seems to me you are changing the documented default. You cannot
do that, this is ABI.

   Andrew

_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip