Re: [PATCH i-g-t] tests/i915_pm_freq_api: Set min/max to expected values

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

On 9/20/2023 7:07 AM, Rodrigo Vivi wrote:
> On Mon, Sep 18, 2023 at 12:02:59PM -0700, Vinay Belgaumkar wrote:
> > A prior(rps) test leaves the system in a bad state causing failures
> > in the basic test.
> Why?
>
> What was the freq immediately before the failure that made the
> machine to be busted and not accept the new freq request?
>
> Maybe we should use this information to limit the freq requests
> that we accept instead of workaround the test case. Otherwise
> we are at risk of users selecting the bad freq that let " the
> system in a bad state"...

i915_pm_rps (waitboost) test sets soft max_freq to some value less than 
RP0 and then fails. The restore on failure does not work properly as the 
test is not multitile capable(it sets the root sysfs entry instead of 
using the per tile entry). Then, the current test (i915_pm_freq_api --r 
basic-api) tries to set min_freq to RP0 as part of normal testing. This 
fails as soft_max is < RP0.

There is some non-trivial effort needed to convert i915_pm_rps to 
multitile, and this is a BAT failure, hence adding the quick fix to 
ensure the test runs with a good pre-environment.

Thanks,

Vinay.

> > Set min/max to expected values before running it.
> > Test will restore values at the end.
> >
> > Link: https://gitlab.freedesktop.org/drm/intel/-/issues/8670
> >
> > Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@xxxxxxxxx>
> > ---
> >   tests/intel/i915_pm_freq_api.c | 8 ++++++--
> >   1 file changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/tests/intel/i915_pm_freq_api.c b/tests/intel/i915_pm_freq_api.c
> > index 03bd0d05b..6018692a2 100644
> > --- a/tests/intel/i915_pm_freq_api.c
> > +++ b/tests/intel/i915_pm_freq_api.c
> > @@ -55,7 +55,11 @@ static void test_freq_basic_api(int dirfd, int gt)
> >   	rpn = get_freq(dirfd, RPS_RPn_FREQ_MHZ);
> >   	rp0 = get_freq(dirfd, RPS_RP0_FREQ_MHZ);
> >   	rpe = get_freq(dirfd, RPS_RP1_FREQ_MHZ);
> > -	igt_debug("GT: %d, RPn: %d, RPe: %d, RP0: %d", gt, rpn, rpe, rp0);
> > +	igt_debug("GT: %d, RPn: %d, RPe: %d, RP0: %d\n", gt, rpn, rpe, rp0);
> > +
> > +	/* Set min/max to RPn, RP0 for baseline behavior */
> > +	igt_assert(set_freq(dirfd, RPS_MIN_FREQ_MHZ, rpn) > 0);
> > +	igt_assert(set_freq(dirfd, RPS_MAX_FREQ_MHZ, rp0) > 0);
> >   
> >   	/*
> >   	 * Negative bound tests
> > @@ -170,7 +174,7 @@ igt_main
> >   		for_each_sysfs_gt_dirfd(i915, dirfd, gt) {
> >   			stash_min[gt] = get_freq(dirfd, RPS_MIN_FREQ_MHZ);
> >   			stash_max[gt] = get_freq(dirfd, RPS_MAX_FREQ_MHZ);
> > -			igt_debug("GT: %d, min: %d, max: %d", gt, stash_min[gt], stash_max[gt]);
> > +			igt_debug("GT: %d, min: %d, max: %d\n", gt, stash_min[gt], stash_max[gt]);
> >   			igt_pm_ignore_slpc_efficient_freq(i915, dirfd, true);
> >   		}
> >   		igt_install_exit_handler(restore_sysfs_freq);
> > --
> > 2.38.1