Subject: Re: [PATCH net 13/13] net: dwmac-loongson: Perceive zero IRQ as invalid

From: Piotr Raczynski <[email-masked]>
Date: Tue, 14 Mar 2023 09:20:42 +0100

On Tue, Mar 14, 2023 at 01:42:37AM +0300, Serge Semin wrote:
> Linux kernel defines zero IRQ number as invalid in case if IRQ couldn't be
> mapped. Fix that for Loongson PCI MAC specific IRQs request procedure.
> 

Looks a little odd but as I also checked and kernel does seem to treat
zero as mapping failure instead of -WHATEVER.

Fix looks fine.

Reviewed-by: Piotr Raczynski <[email-masked]>

> Fixes: 30bba69d7db4 ("stmmac: pci: Add dwmac support for Loongson")
> Signed-off-by: Serge Semin <[email-masked]>
> ---
>  drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
> index a25c187d3185..907bdfcc07e9 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson.c
> @@ -127,20 +127,20 @@ static int loongson_dwmac_probe(struct pci_dev *pdev, const struct pci_device_id
>  	res.addr = pcim_iomap_table(pdev)[0];
>  
>  	res.irq = of_irq_get_byname(np, "macirq");
> -	if (res.irq < 0) {
> +	if (res.irq <= 0) {
>  		dev_err(&pdev->dev, "IRQ macirq not found\n");
>  		ret = -ENODEV;
>  		goto err_disable_msi;
>  	}
>  
>  	res.wol_irq = of_irq_get_byname(np, "eth_wake_irq");
> -	if (res.wol_irq < 0) {
> +	if (res.wol_irq <= 0) {
>  		dev_info(&pdev->dev, "IRQ eth_wake_irq not found, using macirq\n");
>  		res.wol_irq = res.irq;
>  	}
>  
>  	res.lpi_irq = of_irq_get_byname(np, "eth_lpi");
> -	if (res.lpi_irq < 0) {
> +	if (res.lpi_irq <= 0) {
>  		dev_err(&pdev->dev, "IRQ eth_lpi not found\n");
>  		ret = -ENODEV;
>  		goto err_disable_msi;
> -- 
> 2.39.2
> 
>