Re: [v4,1/4] net: stmmac: platform: read channels irq

[Jakub Kicinski]

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---
net: stmmac: platform: read channels irq

This patch reads IRQ resources for all rx/tx channels to allow Multi-IRQ
mode for platform glue drivers.

> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> index 8979a50b5507..94854bfb6e0d 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c

[ ... ]

> +	/* RX channels irq */
> +	for (i = 0; i < MTL_MAX_RX_QUEUES; i++) {
> +		scnprintf(name, sizeof(name), "rx-queue-%d", i);
> +		stmmac_res->rx_irq[i] = platform_get_irq_byname_optional(pdev,
> +									 name);
> +		if (stmmac_res->rx_irq[i] <= 0) {
> +			if (stmmac_res->rx_irq[i] == -EPROBE_DEFER)
> +				return -EPROBE_DEFER;
> +			dev_dbg(&pdev->dev, "IRQ rx-queue-%d not found\n", i);
> +
> +			/* Stop on first unset rx-queue-%i property member */
> +			break;
> +		}
> +	}

When platform_get_irq_byname_optional() returns a negative error like
-ENXIO, that value is stored in stmmac_res->rx_irq[i] before the break.

In stmmac_request_irq_multi_msi(), the check is:

    if (priv->rx_irq[i] == 0)
        continue;
    ret = request_irq(priv->rx_irq[i], ...);

Should the negative value be cleared before the break? Otherwise if
rx_queues_to_use exceeds the number of defined IRQs, the negative error
code could be passed to request_irq().

> +
> +	/* TX channels irq */
> +	for (i = 0; i < MTL_MAX_TX_QUEUES; i++) {
> +		scnprintf(name, sizeof(name), "tx-queue-%d", i);
> +		stmmac_res->tx_irq[i] = platform_get_irq_byname_optional(pdev,
> +									 name);
> +		if (stmmac_res->tx_irq[i] <= 0) {
> +			if (stmmac_res->tx_irq[i] == -EPROBE_DEFER)
> +				return -EPROBE_DEFER;
> +			dev_dbg(&pdev->dev, "IRQ tx-queue-%d not found\n", i);
> +
> +			/* Stop on first unset tx-queue-%i property member */
> +			break;
> +		}
> +	}

Same question here for tx_irq[i].
-- 
pw-bot: cr