Re: [PATCH] fw_cfg: use __ATTR_RO_MODE to define rev sysfs

[Michael S. Tsirkin]

On Tue, Feb 26, 2019 at 03:31:59PM +0800, Wei Yang wrote:
> Leverage __ATTR_RO_MODE to define rev sysfs instead of using open code
> to define the attribute.
> 
> Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
> ---
>  drivers/firmware/qemu_fw_cfg.c | 13 ++++---------
>  1 file changed, 4 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c
> index 039e0f91dba8..a1293cbd7adb 100644
> --- a/drivers/firmware/qemu_fw_cfg.c
> +++ b/drivers/firmware/qemu_fw_cfg.c
> @@ -296,18 +296,13 @@ static int fw_cfg_do_platform_probe(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -static ssize_t fw_cfg_showrev(struct kobject *k, struct attribute *a, char *buf)
> +static ssize_t fw_cfg_rev_show(struct kobject *k, struct kobj_attribute *a,
> +			       char *buf)
>  {
>  	return sprintf(buf, "%u\n", fw_cfg_rev);
>  }
> -
> -static const struct {
> -	struct attribute attr;
> -	ssize_t (*show)(struct kobject *k, struct attribute *a, char *buf);
> -} fw_cfg_rev_attr = {
> -	.attr = { .name = "rev", .mode = S_IRUSR },
> -	.show = fw_cfg_showrev,
> -};
> +static const struct kobj_attribute fw_cfg_rev_attr =
> +	__ATTR_RO_MODE(fw_cfg_rev, 0400);
>  
>  /* fw_cfg_sysfs_entry type */
>  struct fw_cfg_sysfs_entry {


Looks like this will change the name from "rev" to "fw_cfg_rev".
That's a userspace visible change which we should not do lightly.
> -- 
> 2.19.1