Re: [PATCH v2] net: ethernet: mtk_eth_soc: support named IRQs

[Daniel Golle <daniel@makrotopia.org>]

On Sun, Jun 15, 2025 at 10:45:19AM +0200, Frank Wunderlich wrote:
> From: Frank Wunderlich <frank-w@public-files.de>
> 
> Add named interrupts and keep index based fallback for exiting devicetrees.
> 
> Currently only rx and tx IRQs are defined to be used with mt7988, but
> later extended with RSS/LRO support.
> 
> Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
> Reviewed-by: Simon Horman <horms@kernel.org>
> ---
> v2:
> - move irqs loading part into own helper function
> - reduce indentation
> - place mtk_get_irqs helper before the irq_handler (note for simon)
> ---
>  drivers/net/ethernet/mediatek/mtk_eth_soc.c | 39 +++++++++++++++------
>  1 file changed, 28 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> index b76d35069887..81ae8a6fe838 100644
> --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> @@ -3337,6 +3337,30 @@ static void mtk_tx_timeout(struct net_device *dev, unsigned int txqueue)
>  	schedule_work(&eth->pending_work);
>  }
>  
> +static int mtk_get_irqs(struct platform_device *pdev, struct mtk_eth *eth)
> +{
> +	int i;
> +
> +	eth->irq[1] = platform_get_irq_byname(pdev, "tx");
> +	eth->irq[2] = platform_get_irq_byname(pdev, "rx");

In addition to Lorenzo's comment to reduce the array to the actually used
IRQs, I think it would be nice to introduce precompiler macros for the irq
array index, ie. once the array is reduce to size 2 it could be something
like

#define MTK_ETH_IRQ_SHARED 0
#define MTK_ETH_IRQ_TX 0
#define MTK_ETH_IRQ_RX 1
#define __MTK_ETH_IRQ_MAX MTK_ETH_IRQ_RX

That would make all the IRQ code more readable than having to deal with
numerical values.

> +	if (eth->irq[1] >= 0 && eth->irq[2] >= 0)
> +		return 0;
> +
> +	for (i = 0; i < 3; i++) {
> +		if (MTK_HAS_CAPS(eth->soc->caps, MTK_SHARED_INT) && i > 0)
> +			eth->irq[i] = eth->irq[0];
> +		else
> +			eth->irq[i] = platform_get_irq(pdev, i);
> +
> +		if (eth->irq[i] < 0) {
> +			dev_err(&pdev->dev, "no IRQ%d resource found\n", i);
> +			return -ENXIO;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
>  static irqreturn_t mtk_handle_irq_rx(int irq, void *_eth)
>  {
>  	struct mtk_eth *eth = _eth;
> @@ -5106,17 +5130,10 @@ static int mtk_probe(struct platform_device *pdev)
>  		}
>  	}
>  
> -	for (i = 0; i < 3; i++) {
> -		if (MTK_HAS_CAPS(eth->soc->caps, MTK_SHARED_INT) && i > 0)
> -			eth->irq[i] = eth->irq[0];
> -		else
> -			eth->irq[i] = platform_get_irq(pdev, i);
> -		if (eth->irq[i] < 0) {
> -			dev_err(&pdev->dev, "no IRQ%d resource found\n", i);
> -			err = -ENXIO;
> -			goto err_wed_exit;
> -		}
> -	}
> +	err = mtk_get_irqs(pdev, eth);
> +	if (err)
> +		goto err_wed_exit;
> +
>  	for (i = 0; i < ARRAY_SIZE(eth->clks); i++) {
>  		eth->clks[i] = devm_clk_get(eth->dev,
>  					    mtk_clks_source_name[i]);
> -- 
> 2.43.0
>