[igt-dev] [PATCH i-g-t 1/2] [CI] tests/pm_backlight.c: Fix brightness failure with system suspend

[Daniel Vetter]

On Wed, Oct 17, 2018 at 11:44 AM Chris Wilson <chris at chris-wilson.co.uk> wrote:
>
> Quoting Jyoti Yadav (2018-10-17 10:13:20)
> > This patch tries to fix the faliure occuring during subtest
> > "fade_with_suspend". Failure is occuring because, brightness
> > value is being checked before driver initializes fully after resume.
> >
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107847
> > Signed-off-by: Jyoti Yadav <jyoti.r.yadav at intel.com>
> > ---
> >  tests/pm_backlight.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/tests/pm_backlight.c b/tests/pm_backlight.c
> > index 32808cd..ec047b3 100644
> > --- a/tests/pm_backlight.c
> > +++ b/tests/pm_backlight.c
> > @@ -183,6 +183,7 @@ test_fade_with_suspend(struct context *context, igt_output_t *output)
> >         igt_require(igt_wait_for_pm_status(IGT_RUNTIME_PM_STATUS_SUSPENDED));
> >
> >         igt_system_suspend_autoresume(SUSPEND_STATE_MEM, SUSPEND_TEST_NONE);
> > +       igt_require(igt_wait_for_pm_status(IGT_RUNTIME_PM_STATUS_ACTIVE));
>
> Why would the device be active on system resume if it was asleep
> beforehand? In fact, that sounds like the opposite of what we would like
> ;)

This also looks like papering over a kernel bug I think. Or a test
bug. Doing an igt_require after we've done a rather expensive
operation already (suspend/resume cycle) is definitely not correct -
we should know what should work, not dynamically skip the test if it
turns out it didn't work.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch