Re: [igt-dev] [PATCH i-g-t 3/4] tests/gem_ctx_freq: Disable SLPC efficient freq for the test

["Belgaumkar, Vinay" <vinay.belgaumkar@intel.com>]

On 6/5/2023 6:21 PM, Ashutosh Dixit wrote:
> When SLPC efficient freq is enabled, GPU frequencies can be outside the
> min/max range set from sysfs. Any test which compares actual GPU frequency
> against set frequencies is therefore meaninful only when SLPC efficient
> freq is disabled.
>
> Bug: https://gitlab.freedesktop.org/drm/intel/-/issues/6786
> Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
> ---
>   tests/i915/gem_ctx_freq.c | 15 ++++++++++++++-
>   1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/tests/i915/gem_ctx_freq.c b/tests/i915/gem_ctx_freq.c
> index b2f6c2af55e1..6dfcf4187d4b 100644
> --- a/tests/i915/gem_ctx_freq.c
> +++ b/tests/i915/gem_ctx_freq.c
> @@ -131,6 +131,15 @@ static bool get_sysfs_freq(int dirfd, uint32_t *min, uint32_t *max)
>   		igt_sysfs_rps_scanf(dirfd, RPS_MAX_FREQ_MHZ, "%u", max) == 1);
>   }
>   
> +static void slpc_ignore_efficient_freq(int dirfd, bool val)
> +{
> +	if (!(gem_using_guc_submission(i915) && i915_is_slpc_enabled(i915)))
> +		return;
There was a reason why I had both, not remembering now.
> +
> +	igt_require(igt_sysfs_has_attr(dirfd, "slpc_ignore_eff_freq"));
> +	igt_assert(igt_sysfs_set_u32(dirfd, "slpc_ignore_eff_freq", val));
> +}

Can we add this as a helper in lib/igt_pm.c? I suspect there might be 
other present/future tests that may need to use this.

Thanks,

Vinay.

> +
>   static void sysfs_range(int dirfd, int gt)
>   {
>   #define N_STEPS 10
> @@ -147,9 +156,11 @@ static void sysfs_range(int dirfd, int gt)
>   	 * The sysfs interface sets the global limits and overrides the
>   	 * user's request. So we can to check that if the user requests
>   	 * a range outside of the sysfs, the requests are only run at the
> -	 * constriained sysfs range.
> +	 * constrained sysfs range. With GuC SLPC this requires disabling
> +	 * efficient freq.
>   	 */
>   
> +	slpc_ignore_efficient_freq(dirfd, true);
>   	igt_require(get_sysfs_freq(dirfd, &sys_min, &sys_max));
>   	igt_info("System min freq: %dMHz; max freq: %dMHz\n", sys_min, sys_max);
>   
> @@ -199,6 +210,8 @@ static void __restore_sysfs_freq(int dirfd)
>   {
>   	char buf[256];
>   
> +	slpc_ignore_efficient_freq(dirfd, false);
> +
>   	if (igt_sysfs_read(sysfs, "gt_RPn_freq_mhz", buf, sizeof(buf)) > 0)
>   		igt_sysfs_rps_set(dirfd, RPS_MIN_FREQ_MHZ, buf);
>