Re: [PATCH i-g-t] tests/xe_gt_freq: Avoid RPe usage in subtests

["Nilawar, Badal" <badal.nilawar@intel.com>]

Hi Vinay,

On 24-07-2024 22:29, Vinay Belgaumkar wrote:
> We are seeing several instances where the RPe, which can be altered by
> pcode dynamically, is causing subtests to fail randomly. Instead of relying
> on it, we can use a mid frequency value for these subtests and avoid these
> failures.
> 
> Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2262
> Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2256
> 
> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
> ---
>   tests/intel/xe_gt_freq.c | 37 +++++++++++++++++++++++++++++--------
>   1 file changed, 29 insertions(+), 8 deletions(-)
> 
> diff --git a/tests/intel/xe_gt_freq.c b/tests/intel/xe_gt_freq.c
> index 93ebb5ed0..442f5658f 100644
> --- a/tests/intel/xe_gt_freq.c
> +++ b/tests/intel/xe_gt_freq.c
> @@ -26,6 +26,9 @@
>   #include <sys/time.h>
>   
>   #define MAX_N_EXEC_QUEUES 16
> +#define GT_FREQUENCY_MULTIPLIER	50
> +#define GT_FREQUENCY_SCALER	3
> +#define FREQ_UNIT_MHZ (GT_FREQUENCY_MULTIPLIER / GT_FREQUENCY_SCALER)
>   
>   /*
>    * Too many intermediate components and steps before freq is adjusted
> @@ -70,6 +73,16 @@ static uint32_t get_freq(int fd, int gt_id, const char *freq_name)
>   	return freq;
>   }
>   
> +static bool within_expected_range(uint32_t freq, uint32_t val)
> +{
> +	/*
> +	 * GT Frequencies are requested at units of 16.66 Mhz, so allow
> +	 * that tolerance.
> +	 */
> +	return (freq <= val + FREQ_UNIT_MHZ) ||
> +		(freq >= val - FREQ_UNIT_MHZ);
> +}
> +
>   static uint32_t rpe(int fd, int gt_id)
>   {
>   	return get_freq(fd, gt_id, "rpe");
> @@ -128,6 +141,8 @@ static void test_freq_basic_api(int fd, int gt_id)
>   {
>   	uint32_t rpn = get_freq(fd, gt_id, "rpn");
>   	uint32_t rp0 = get_freq(fd, gt_id, "rp0");
> +	uint32_t rpmid = (rp0 + rpn) / 2;
> +	uint32_t min_freq, max_freq;
>   
>   	/*
>   	 * Negative bound tests
> @@ -142,16 +157,18 @@ static void test_freq_basic_api(int fd, int gt_id)
>   	/* Assert min requests are respected from rp0 to rpn */
>   	igt_assert(set_freq(fd, gt_id, "min", rp0) > 0);
>   	igt_assert(get_freq(fd, gt_id, "min") == rp0);
> -	igt_assert(set_freq(fd, gt_id, "min", rpe(fd, gt_id)) > 0);
> -	igt_assert(get_freq(fd, gt_id, "min") == rpe(fd, gt_id));
> +	igt_assert(set_freq(fd, gt_id, "min", rpmid) > 0);
> +	min_freq = get_freq(fd, gt_id, "min");
> +	igt_assert(within_expected_range(min_freq, rpmid));
>   	igt_assert(set_freq(fd, gt_id, "min", rpn) > 0);
>   	igt_assert(get_freq(fd, gt_id, "min") == rpn);
>   
>   	/* Assert max requests are respected from rpn to rp0 */
>   	igt_assert(set_freq(fd, gt_id, "max", rpn) > 0);
>   	igt_assert(get_freq(fd, gt_id, "max") == rpn);
> -	igt_assert(set_freq(fd, gt_id, "max", rpe(fd, gt_id)) > 0);
> -	igt_assert(get_freq(fd, gt_id, "max") == rpe(fd, gt_id));
> +	igt_assert(set_freq(fd, gt_id, "max", rpmid) > 0);
> +	max_freq = get_freq(fd, gt_id, "min");
> +	igt_assert(within_expected_range(max_freq, rpmid));
>   	igt_assert(set_freq(fd, gt_id, "max", rp0) > 0);
>   	igt_assert(get_freq(fd, gt_id, "max") == rp0);
>   }
> @@ -168,6 +185,8 @@ static void test_freq_fixed(int fd, int gt_id, bool gt_idle)
>   {
>   	uint32_t rpn = get_freq(fd, gt_id, "rpn");
>   	uint32_t rp0 = get_freq(fd, gt_id, "rp0");
> +	uint32_t rpmid = (rp0 + rpn) / 2;
> +	uint32_t cur_freq, act_freq;
>   
>   	igt_debug("Starting testing fixed request\n");
>   
> @@ -190,17 +209,19 @@ static void test_freq_fixed(int fd, int gt_id, bool gt_idle)
>   		igt_assert(get_freq(fd, gt_id, "act") == rpn);
>   	}
>   
> -	igt_assert(set_freq(fd, gt_id, "min", rpe(fd, gt_id)) > 0);
> -	igt_assert(set_freq(fd, gt_id, "max", rpe(fd, gt_id)) > 0);
> +	igt_assert(set_freq(fd, gt_id, "min", rpmid) > 0);
> +	igt_assert(set_freq(fd, gt_id, "max", rpmid) > 0);
>   	usleep(ACT_FREQ_LATENCY_US);
> -	igt_assert(get_freq(fd, gt_id, "cur") == rpe(fd, gt_id));
> +	cur_freq = get_freq(fd, gt_id, "cur");
> +	igt_assert(within_expected_range(cur_freq, rpmid));
>   
>   	if (gt_idle) {
>   		igt_assert_f(igt_wait(xe_is_gt_in_c6(fd, gt_id), 1000, 10),
>   			     "GT %d should be in C6\n", gt_id);
>   		igt_assert(get_freq(fd, gt_id, "act") == 0);
>   	} else {
> -		igt_assert(get_freq(fd, gt_id, "act") == rpe(fd, gt_id));
> +		act_freq = get_freq(fd, gt_id, "act");
> +		igt_assert(within_expected_range(act_freq, rpmid));
>   	}
>   
>   	igt_assert(set_freq(fd, gt_id, "min", rp0) > 0);

We should cover freq range subtests as well.

https://intel-gfx-ci.01.org/tree/intel-xe/xe-1667-9f8e597a1c39d7e316f9479e6f627c15dbc58e1d/shard-lnl-7/igt@xe_gt_freq@freq_range_exec.html

Regards,
Badal