[PATCH] acpi/method: check full and battery power if acpi_video0 exists

[Colin Ian King]

On 19/04/2019 06:57, Alex Hung wrote:
> 8b9e5e4c07f4 added checks for full and battery power in _BCL list,
> but ACPI spec does not necessary ask them to be included (please
> see examples in ACPI spec B.5.2). However, Linux kernel relies on this
> behaviours.
> 
> Let's only check full and battery power only if acpi_video0 interface is
> used.
> 
> Signed-off-by: Alex Hung <alex.hung at canonical.com>
> ---
>  src/acpi/method/method.c | 64 ++++++++++++++++++++++------------------
>  1 file changed, 35 insertions(+), 29 deletions(-)
> 
> diff --git a/src/acpi/method/method.c b/src/acpi/method/method.c
> index 635c4813..5a4de7b3 100644
> --- a/src/acpi/method/method.c
> +++ b/src/acpi/method/method.c
> @@ -5741,6 +5741,7 @@ static void method_test_BCL_return(
>  	bool ascending_levels = false;
>  	bool matching_levels;
>  	char *str = NULL;
> +	DIR *acpi_video_dir;
>  
>  	FWTS_UNUSED(private);
>  
> @@ -5791,40 +5792,45 @@ static void method_test_BCL_return(
>  		failed = true;
>  	}
>  
> -	matching_levels = false;
> -	for (i = 2; i < obj->Package.Count; i++) {
> -		if (obj->Package.Elements[0].Integer.Value ==
> -		    obj->Package.Elements[i].Integer.Value) {
> -			matching_levels = true;
> -			break;
> +	acpi_video_dir = opendir("/sys/class/backlight/acpi_video0");

Does this sysfs interface exist for the all kernel releases that we
support?

Also, rather than an expensive opendir()/closedir(), it may be
preferable to just use access() or stat() to check if the sysfs
directory exists.

> +	if (acpi_video_dir) {
> +		matching_levels = false;
> +		for (i = 2; i < obj->Package.Count; i++) {
> +			if (obj->Package.Elements[0].Integer.Value ==
> +			    obj->Package.Elements[i].Integer.Value) {
> +				matching_levels = true;
> +				break;
> +			}
>  		}
> -	}
>  
> -	if (!matching_levels) {
> -		failed = true;
> -		fwts_failed(fw, LOG_LEVEL_CRITICAL,
> -			"Method_BCLFullNotInList",
> -			"brightness level on full power (%" PRIu64
> -			") is not in brightness levels.",
> -			obj->Package.Elements[0].Integer.Value);
> -	}
> +		if (!matching_levels) {
> +			failed = true;
> +			fwts_failed(fw, LOG_LEVEL_CRITICAL,
> +				"Method_BCLFullNotInList",
> +				"brightness level on full power (%" PRIu64
> +				") is not in brightness levels.",
> +				obj->Package.Elements[0].Integer.Value);
> +		}
>  
> -	matching_levels = false;
> -	for (i = 2; i < obj->Package.Count; i++) {
> -		if (obj->Package.Elements[1].Integer.Value ==
> -		    obj->Package.Elements[i].Integer.Value) {
> -			matching_levels = true;
> -			break;
> +		matching_levels = false;
> +		for (i = 2; i < obj->Package.Count; i++) {
> +			if (obj->Package.Elements[1].Integer.Value ==
> +			    obj->Package.Elements[i].Integer.Value) {
> +				matching_levels = true;
> +				break;
> +			}
>  		}
> -	}
>  
> -	if (!matching_levels) {
> -		failed = true;
> -		fwts_failed(fw, LOG_LEVEL_CRITICAL,
> -			"Method_BCLBatteryNotInList",
> -			"brightness level on battery (%" PRIu64
> -			") is not in brightness levels.",
> -			obj->Package.Elements[1].Integer.Value);
> +		if (!matching_levels) {
> +			failed = true;
> +			fwts_failed(fw, LOG_LEVEL_CRITICAL,
> +				"Method_BCLBatteryNotInList",
> +				"brightness level on battery (%" PRIu64
> +				") is not in brightness levels.",
> +				obj->Package.Elements[1].Integer.Value);
> +		}
> +
> +		closedir(acpi_video_dir);
>  	}
>  
>  	fwts_log_info(fw, "Brightness levels for %s:" ,name);
>