Re: [PATCH 2/3] net: stmmac: qcom-ethqos: Enable RX programmable swap on qcs615

[Yijie Yang]

On 2024-12-25 19:37, Krzysztof Kozlowski wrote:
> On 25/12/2024 11:04, Yijie Yang wrote:
>
> >   static int qcom_ethqos_probe(struct platform_device *pdev)
> >   {
> > -	struct device_node *np = pdev->dev.of_node;
> > +	struct device_node *np = pdev->dev.of_node, *root;
> >   	const struct ethqos_emac_driver_data *data;
> >   	struct plat_stmmacenet_data *plat_dat;
> >   	struct stmmac_resources stmmac_res;
> > @@ -810,6 +805,15 @@ static int qcom_ethqos_probe(struct platform_device *pdev)
> >   	ret = of_get_phy_mode(np, &ethqos->phy_mode);
> >   	if (ret)
> >   		return dev_err_probe(dev, ret, "Failed to get phy mode\n");
> > +
> > +	root = of_find_node_by_path("/");
> > +	if (root && of_device_is_compatible(root, "qcom,sa8540p-ride"))
>
>
> Nope, your drivers are not supposed to poke root compatibles. Drop and
> fix your driver to behave correctly for all existing devices.

Since this change introduces a new flag in the DTS, we must maintain ABI 
compatibility with the kernel. The new flag is specific to the board, so 
I need to ensure root nodes are matched to allow older boards to 
continue functioning as before. I'm happy to adopt that approach if 
there are any more elegant solutions.

> > +		ethqos->needs_rx_prog_swap = true;
> > +	else
> > +		ethqos->needs_rx_prog_swap =
> Best regards,
> Krzysztof

--
Best Regards,
Yijie