Re: [PATCH net-next v2 3/4] net: stmmac: Add support for TX/RX channel interrupt

[Serge Semin]

On Fri, Jan 05, 2024 at 03:09:24PM +0800, Leong Ching Swee wrote:
> From: Swee Leong Ching <leong.ching.swee@xxxxxxxxx>
> 
> Enable TX/RX channel interrupt registration for MAC that interrupts CPU
> through shared peripheral interrupt (SPI).
> 
> Per channel interrupts and interrupt-names are registered through,
> Eg: 4 tx and 4 rx channels:
> interrupts = <GIC_SPI 100 IRQ_TYPE_LEVEL_HIGH>,
>              <GIC_SPI 101 IRQ_TYPE_LEVEL_HIGH>,
>              <GIC_SPI 102 IRQ_TYPE_LEVEL_HIGH>,
>              <GIC_SPI 103 IRQ_TYPE_LEVEL_HIGH>;
>              <GIC_SPI 104 IRQ_TYPE_LEVEL_HIGH>;
>              <GIC_SPI 105 IRQ_TYPE_LEVEL_HIGH>;
>              <GIC_SPI 106 IRQ_TYPE_LEVEL_HIGH>;
>              <GIC_SPI 107 IRQ_TYPE_LEVEL_HIGH>;
> interrupt-names = "dma_tx0",
>                   "dma_tx1",
>                   "dma_tx2",
>                   "dma_tx3",
>                   "dma_rx0",
>                   "dma_rx1",
>                   "dma_rx2",
>                   "dma_rx3";
> 
> Signed-off-by: Teoh Ji Sheng <ji.sheng.teoh@xxxxxxxxx>
> Signed-off-by: Swee Leong Ching <leong.ching.swee@xxxxxxxxx>
> ---
>  .../ethernet/stmicro/stmmac/stmmac_platform.c | 28 +++++++++++++++++++
>  1 file changed, 28 insertions(+)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> index 70eadc83ca68..ae6859153e98 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> @@ -710,6 +710,10 @@ EXPORT_SYMBOL_GPL(devm_stmmac_probe_config_dt);
>  int stmmac_get_platform_resources(struct platform_device *pdev,
>  				  struct stmmac_resources *stmmac_res)
>  {

> +	char irq_name[9];
> +	int i;
> +	int irq;
> +

Reverse xmas tree please. Also what the point in having "i" and "irq"
defined separately? Wouldn't it be better to merge them into a single
statement:
+	char irq_name[9];
+	int i, irq;

>  	memset(stmmac_res, 0, sizeof(*stmmac_res));
>  
>  	/* Get IRQ information early to have an ability to ask for deferred
> @@ -743,6 +747,30 @@ int stmmac_get_platform_resources(struct platform_device *pdev,
>  		dev_info(&pdev->dev, "IRQ eth_lpi not found\n");
>  	}
>  

> +	/* For RX Channel */

Why haven't you added a more descriptive comment as I suggested on v1:

+	/* Get optional Tx/Rx DMA per-channel IRQs, which otherwise
+	 * are supposed to be delivered via the common MAC IRQ line
+	 */

?

> +	for (i = 0; i < MTL_MAX_RX_QUEUES; i++) {
> +		snprintf(irq_name, sizeof(irq_name), "dma_rx%i", i);
> +		irq = platform_get_irq_byname_optional(pdev, irq_name);
> +		if (irq == -EPROBE_DEFER)
> +			return irq;
> +		else if (irq < 0)
> +			break;
> +
> +		stmmac_res->rx_irq[i] = irq;
> +	}
> +

> +	/* For TX Channel */

* see the comment above

-Serge(y)

> +	for (i = 0; i < MTL_MAX_TX_QUEUES; i++) {
> +		snprintf(irq_name, sizeof(irq_name), "dma_tx%i", i);
> +		irq = platform_get_irq_byname_optional(pdev, irq_name);
> +		if (irq == -EPROBE_DEFER)
> +			return irq;
> +		else if (irq < 0)
> +			break;
> +
> +		stmmac_res->tx_irq[i] = irq;
> +	}
> +
>  	stmmac_res->addr = devm_platform_ioremap_resource(pdev, 0);
>  
>  	return PTR_ERR_OR_ZERO(stmmac_res->addr);
> -- 
> 2.34.1
> 
>