Subject: Re: [PATCH net-next 04/13] sunhme: Return an ERR_PTR from quattro_pci_find

From: Rolf Eike Beer <[email-masked]>
Date: Mon, 19 Sep 2022 15:11:35 +0200

Am Montag, 19. September 2022, 01:26:17 CEST schrieb Sean Anderson:
> In order to differentiate between a missing bridge and an OOM condition,
> return ERR_PTRs from quattro_pci_find. This also does some general linting
> in the area.
> 
> Signed-off-by: Sean Anderson <[email-masked]>
> ---
> 
>  drivers/net/ethernet/sun/sunhme.c | 33 +++++++++++++++++++------------
>  1 file changed, 20 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/net/ethernet/sun/sunhme.c
> b/drivers/net/ethernet/sun/sunhme.c index 1fc16801f520..52247505d08e 100644
> --- a/drivers/net/ethernet/sun/sunhme.c
> +++ b/drivers/net/ethernet/sun/sunhme.c
> @@ -2569,30 +2569,33 @@ static void quattro_sbus_free_irqs(void)
>  #ifdef CONFIG_PCI
>  static struct quattro *quattro_pci_find(struct pci_dev *pdev)
>  {
> +	int i;
>  	struct pci_dev *bdev = pdev->bus->self;
>  	struct quattro *qp;
> 
> -	if (!bdev) return NULL;
> +	if (!bdev)
> +		return ERR_PTR(-ENODEV);
> +
>  	for (qp = qfe_pci_list; qp != NULL; qp = qp->next) {
>  		struct pci_dev *qpdev = qp->quattro_dev;
> 
>  		if (qpdev == bdev)
>  			return qp;
>  	}
> +
>  	qp = kmalloc(sizeof(struct quattro), GFP_KERNEL);
> -	if (qp != NULL) {
> -		int i;
> +	if (!qp)
> +		return ERR_PTR(-ENOMEM);
> 
> -		for (i = 0; i < 4; i++)
> -			qp->happy_meals[i] = NULL;
> +	for (i = 0; i < 4; i++)
> +		qp->happy_meals[i] = NULL;

I know you are only reindenting it, but I dislike moving the variable up to 
the top of the function. Since the kernel is C99 meanwhile the variable could 
be declared just in the for loop. And when touching this anyway I think we 
could get rid of the magic "4" by using ARRAY_SIZE(qp->happy_meals). Or just 
replace the whole thing with memset(qp->happy_meals, 0, sizeof(qp-
>happy_meals)).

Eike