Re: [PATCH i-g-t] tests/intel/intel_hwmon: Warn on zero-valued numeric attributes

Hi Karthik,

On 05-08-2026 19:28, Karthik Poosa wrote:
> Add a check for numeric hwmon attribute values and emit a warning when a
> valid numeric attribute reports 0.
> This acts as a sanity check for valid telemetry data reported via hwmon.
>
> Exclude *_label attributes from this validation to avoid false warnings on
> non-numeric label entries.
>
> Also include the necessary headers required for numeric parsing helpers.
>
> Signed-off-by: Karthik Poosa <[email protected]>
> Assisted-by: GitHub-Copilot:GPT-5.3-Codex
> ---
>   tests/intel/intel_hwmon.c | 31 ++++++++++++++++++++++++++++++-
>   1 file changed, 30 insertions(+), 1 deletion(-)
>
> diff --git a/tests/intel/intel_hwmon.c b/tests/intel/intel_hwmon.c
> index f185c1ca3..6fe57a334 100644
> --- a/tests/intel/intel_hwmon.c
> +++ b/tests/intel/intel_hwmon.c
> @@ -4,6 +4,8 @@
>    */
>   
>   #include <dirent.h>
> +#include <errno.h>
> +#include <stdlib.h>
>   #include <sys/stat.h>
>   #include "igt.h"
>   #include "igt_hwmon.h"
> @@ -26,6 +28,31 @@
>   
>   IGT_TEST_DESCRIPTION("Tests for intel hwmon");
>   
> +static bool value_is_numeric_zero(const char *val)
> +{
> +	char *end;
> +	long long num;
> +
> +	errno = 0;
> +	num = strtoll(val, &end, 10);
> +	if (errno || *val == '\0' || *end != '\0')
> +		return false;
> +
> +	return num == 0;
> +}
> +
> +static bool is_hmwon_label(const char *name)
> +{
> +	const char *suffix = "_label";
> +	size_t name_len = strlen(name);
> +	size_t suffix_len = strlen(suffix);
> +
> +	if (name_len < suffix_len)
> +		return false;
> +
> +	return !strcmp(name + name_len - suffix_len, suffix);
> +}
> +
>   static void check_if_temp_valid(int hwm, char *sysfs_name)
>   {
>   	int32_t cur_temp = 0, limit = 0;
> @@ -64,9 +91,11 @@ static void hwmon_read(int hwm)
>   		igt_assert(igt_sysfs_scanf(hwm, de->d_name, "%127s", val) == 1);
>   		igt_debug("'%s': %s\n", de->d_name, val);
>   
> +		if (!is_hmwon_label(de->d_name) && value_is_numeric_zero(val))

Typo : is_hmwon_label -> is_hwmon_label ?

Thanks,
Soham

> +			igt_warn("hwmon sysfs entry '%s' has zero value\n", de->d_name);
> +
>   		if (!strncmp(de->d_name, "temp", 4))
>   			check_if_temp_valid(hwm, de->d_name);
> -
>   	}
>   	closedir(dir);
>   }