Re: [PATCH 4/4] RDMA: Convert various random sprintf sysfs _show uses to sysfs_emit

[Jason Gunthorpe <jgg@xxxxxxxxxx>]

On Wed, Oct 07, 2020 at 07:36:27PM -0700, Joe Perches wrote:
> diff --git a/drivers/infiniband/hw/mlx4/sysfs.c b/drivers/infiniband/hw/mlx4/sysfs.c
> index 75d50383da89..fc6c98b608d3 100644
> +++ b/drivers/infiniband/hw/mlx4/sysfs.c
> @@ -444,16 +444,17 @@ static ssize_t show_port_pkey(struct mlx4_port *p, struct port_attribute *attr,
>  {
>  	struct port_table_attribute *tab_attr =
>  		container_of(attr, struct port_table_attribute, attr);
> -	ssize_t ret = -ENODEV;
> +	int len;
> +	struct pkey_mgt *m = &p->dev->pkeys;
> +	u8 key = m->virt2phys_pkey[p->slave][p->port_num - 1][tab_attr->index];
>  
> -	if (p->dev->pkeys.virt2phys_pkey[p->slave][p->port_num - 1][tab_attr->index] >=
> -	    (p->dev->dev->caps.pkey_table_len[p->port_num]))
> -		ret = sprintf(buf, "none\n");
> +	if (key >= p->dev->dev->caps.pkey_table_len[p->port_num])
> +		len = sysfs_emit(buf, "none\n");
>  	else
> -		ret = sprintf(buf, "%d\n",
> -			      p->dev->pkeys.virt2phys_pkey[p->slave]
> -			      [p->port_num - 1][tab_attr->index]);
> -	return ret;
> +		len = sysfs_emit(buf, "%d\n",
> +				 p->dev->pkeys.virt2phys_pkey[p->slave]
> +				 [p->port_num - 1][tab_attr->index]);
> +	return len;
>  }

This duplication of virt2phys_pkey can be simplified to:

static ssize_t show_port_pkey(struct mlx4_port *p, struct port_attribute *attr,
			      char *buf)
{
	struct port_table_attribute *tab_attr =
		container_of(attr, struct port_table_attribute, attr);
	struct pkey_mgt *m = &p->dev->pkeys;
	u8 key = m->virt2phys_pkey[p->slave][p->port_num - 1][tab_attr->index];

	if (key >= p->dev->dev->caps.pkey_table_len[p->port_num])
		return sysfs_emit(buf, "none\n");
	return sysfs_emit(buf, "%d\n", key);
}

(I adjusted it)

Jason