[PATCH i-g-t] tests/perf_pmu: Set defaults before frequency test

[Kamil Konieczny]

Hi Vinay,
On 2024-01-11 at 14:20:54 -0800, Vinay Belgaumkar wrote:
> Seeing random issues where this test skips due to invalid
> boost freq at the start. Also ensure that we restore the frequencies at the end.
> 
> v2: Use save/restore functions instead of exit_handler. Adding an
> exit_handler necessitated moving drm_close() into the handler. However,
> the module-reload subtest at the end expects drm-fd to be closed.
> Also setup expected frequencies (Kamil) and address other nits (Kamil)
> 
> Link: https://gitlab.freedesktop.org/drm/intel/-/issues/9432
> Cc: Kamil Konieczny <kamil.konieczny at linux.intel.com>
> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar at intel.com>

Reviewed-by: Kamil Konieczny <kamil.konieczny at linux.intel.com>

> ---
>  tests/intel/perf_pmu.c | 62 +++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 61 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/intel/perf_pmu.c b/tests/intel/perf_pmu.c
> index c6e6a8b77..4ae2b60ae 100644
> --- a/tests/intel/perf_pmu.c
> +++ b/tests/intel/perf_pmu.c
> @@ -2454,12 +2454,69 @@ static void pmu_read(int i915)
>  		for_each_if((e)->class == I915_ENGINE_CLASS_RENDER) \
>  			igt_dynamic_f("%s", e->name)
>  
> +int fd = -1;
> +uint32_t *stash_min, *stash_max, *stash_boost;
> +
> +static void save_sysfs_freq(int i915)
> +{
> +	int gt, num_gts, sysfs, tmp;
> +	uint32_t rpn_freq, rp0_freq;
> +
> +	num_gts = igt_sysfs_get_num_gt(i915);
> +
> +	stash_min = (uint32_t *)malloc(sizeof(uint32_t) * num_gts);
> +	stash_max = (uint32_t *)malloc(sizeof(uint32_t) * num_gts);
> +	stash_boost = (uint32_t *)malloc(sizeof(uint32_t) * num_gts);
> +
> +	/* Save boost, min and max across GTs */
> +	i915_for_each_gt(i915, tmp, gt) {
> +		sysfs = igt_sysfs_gt_open(i915, gt);
> +		igt_require(sysfs >= 0);
> +
> +		stash_min[gt] = igt_sysfs_get_u32(sysfs, "rps_min_freq_mhz");
> +		stash_max[gt] = igt_sysfs_get_u32(sysfs, "rps_max_freq_mhz");
> +		stash_boost[gt] = igt_sysfs_get_u32(sysfs, "rps_boost_freq_mhz");
> +		igt_debug("GT: %d, min: %d, max: %d, boost:%d\n",
> +			  gt, stash_min[gt], stash_max[gt], stash_boost[gt]);
> +
> +		rpn_freq = igt_sysfs_get_u32(sysfs, "rps_RPn_freq_mhz");
> +		rp0_freq = igt_sysfs_get_u32(sysfs, "rps_RP0_freq_mhz");
> +
> +		/* Set pre-conditions, in case frequencies are in non-default state */
> +		igt_require(__igt_sysfs_set_u32(sysfs, "rps_max_freq_mhz", rp0_freq));
> +		igt_require(__igt_sysfs_set_u32(sysfs, "rps_boost_freq_mhz", rp0_freq));
> +		igt_require(__igt_sysfs_set_u32(sysfs, "rps_min_freq_mhz", rpn_freq));
> +
> +		close(sysfs);
> +	}
> +}
> +
> +static void restore_sysfs_freq(int i915)
> +{
> +	int sysfs, gt, tmp;
> +
> +	/* Restore frequencies */
> +	i915_for_each_gt(fd, tmp, gt) {
> +		sysfs = igt_sysfs_gt_open(fd, gt);
> +		igt_require(sysfs >= 0);
> +
> +		igt_require(__igt_sysfs_set_u32(sysfs, "rps_max_freq_mhz", stash_max[gt]));
> +		igt_require(__igt_sysfs_set_u32(sysfs, "rps_min_freq_mhz", stash_min[gt]));
> +		igt_require(__igt_sysfs_set_u32(sysfs, "rps_boost_freq_mhz", stash_boost[gt]));
> +
> +		close(sysfs);
> +	}
> +	free(stash_min);
> +	free(stash_max);
> +	free(stash_boost);
> +}
> +
>  igt_main
>  {
>  	const struct intel_execution_engine2 *e;
>  	unsigned int num_engines = 0;
>  	const intel_ctx_t *ctx = NULL;
> -	int gt, tmp, fd = -1;
> +	int gt, tmp;
>  	int num_gt = 0;
>  
>  	/**
> @@ -2664,12 +2721,15 @@ igt_main
>  	 * Test GPU frequency.
>  	 */
>  	igt_subtest_with_dynamic("frequency") {
> +		save_sysfs_freq(fd);
> +
>  		i915_for_each_gt(fd, tmp, gt) {
>  			igt_dynamic_f("gt%u", gt)
>  				test_frequency(fd, gt);
>  			igt_dynamic_f("idle-gt%u", gt)
>  				test_frequency_idle(fd, gt);
>  		}
> +		restore_sysfs_freq(fd);
>  	}
>  
>  	/**
> -- 
> 2.38.1
>