Re: [PATCH 4/7] platform/x86: hp-bioscfg: Use wmi_instance_count()

[Ilpo Järvinen]

On Mon, 3 Feb 2025, Armin Wolf wrote:

> The WMI core already knows the instance count of a WMI guid.
> Use this information instead of querying all possible instances
> which is slow and might be unreliable.
> 
> Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
> ---
>  drivers/platform/x86/hp/hp-bioscfg/bioscfg.c | 13 +++++--------
>  1 file changed, 5 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
> index 0b277b7e37dd..63c78b4d8258 100644
> --- a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
> +++ b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
> @@ -388,16 +388,13 @@ union acpi_object *hp_get_wmiobj_pointer(int instance_id, const char *guid_strin
>   */
>  int hp_get_instance_count(const char *guid_string)
>  {
> -	union acpi_object *wmi_obj = NULL;
> -	int i = 0;
> +	int ret;
> 
> -	do {
> -		kfree(wmi_obj);
> -		wmi_obj = hp_get_wmiobj_pointer(i, guid_string);
> -		i++;
> -	} while (wmi_obj);
> +	ret = wmi_instance_count(guid_string);
> +	if (ret < 0)
> +		return 0;
> 
> -	return i - 1;
> +	return ret;
>  }

Hi Armin,

While it is the existing way of doing things, I don't like how the error 
is not properly passed on here. And if the error handling is pushed 
upwards to the calling sites, then this entire function becomes useless 
and wmi_instance_count() could be used directly in the callers.

-- 
 i.