Re: [PATCH] tests/intel/xe_gt_freq: Modify test to support new throttle reasons sysfs

[Raag Jadav <raag.jadav@intel.com>]

On Fri, Nov 21, 2025 at 05:19:48PM +0530, Sk Anirban wrote:
> Change throttle_basic_api to read the new atomic reasons attribute
> instead of checking status and individual reason files separately.
> This validates the kernel's TOCTOU-free throttling interface.
> 
> Signed-off-by: Sk Anirban <sk.anirban@intel.com>
> ---
>  tests/intel/xe_gt_freq.c | 45 ++++++++++++----------------------------
>  1 file changed, 13 insertions(+), 32 deletions(-)
> 
> diff --git a/tests/intel/xe_gt_freq.c b/tests/intel/xe_gt_freq.c
> index d0f35b10a..30e359a47 100644
> --- a/tests/intel/xe_gt_freq.c
> +++ b/tests/intel/xe_gt_freq.c
> @@ -47,48 +47,29 @@ static bool within_expected_range(uint32_t freq, uint32_t val)
>  		(freq >= val - FREQ_UNIT_MHZ);
>  }
>  
> -static uint32_t get_throttle(int fd, int gt_id, const char *throttle_file)
> +/**
> + * SUBTEST: throttle_basic_api
> + * Description: Test basic throttle API
> + */
> +
> +static void test_throttle_basic_api(int fd, int gt_id)
>  {
> -	uint32_t val;
> +	char reasons[1024];

A bit too optimistic? :D

Let's use only what we need.

>  	char throttle_attr[40];
>  	int gt_fd;
>  
> -	snprintf(throttle_attr, sizeof(throttle_attr),
> -		 "freq0/throttle/%s", throttle_file);
> +	snprintf(throttle_attr, sizeof(throttle_attr), "freq0/throttle/reasons");
>  	gt_fd = xe_sysfs_gt_open(fd, gt_id);
>  	igt_assert_lte(0, gt_fd);
>  
> -	igt_sysfs_scanf(gt_fd, throttle_attr, "%u", &val);
> +	igt_assert(igt_sysfs_scanf(gt_fd, throttle_attr, "%1023s", reasons) == 1);

Can this be igt_assert_eq()?

> -	igt_debug("gt%d/freq0/throttle/%s: %u\n", gt_id, throttle_file, val);
> +	igt_debug("gt%d/freq0/throttle/reasons: %s\n", gt_id, reasons);
>  
> -	close(gt_fd);
> -	return val;
> -}
> +	if (strcmp(reasons, "none") != 0)

Do you need '!= 0'?

Raag

> +		igt_info("GT %d is being throttled due to: %s\n", gt_id, reasons);
>  
> -/**
> - * SUBTEST: throttle_basic_api
> - * Description: Test basic throttle API
> - */
> -
> -static void test_throttle_basic_api(int fd, int gt_id)
> -{
> -	uint32_t status, reasons;
> -
> -	status = get_throttle(fd, gt_id, "status");
> -	reasons = get_throttle(fd, gt_id, "reason_pl1");
> -	reasons |= get_throttle(fd, gt_id, "reason_pl2");
> -	reasons |= get_throttle(fd, gt_id, "reason_pl4");
> -	reasons |= get_throttle(fd, gt_id, "reason_prochot");
> -	reasons |= get_throttle(fd, gt_id, "reason_ratl");
> -	reasons |= get_throttle(fd, gt_id, "reason_thermal");
> -	reasons |= get_throttle(fd, gt_id, "reason_vr_tdc");
> -	reasons |= get_throttle(fd, gt_id, "reason_vr_thermalert");
> -
> -	if (status)
> -		igt_assert(reasons);
> -	else
> -		igt_assert(!reasons);
> +	close(gt_fd);
>  }
>  
>  /**
> -- 
> 2.43.0
>