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

[Jani Nikula]

On Wed, 17 Oct 2018, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> 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.

It's a test bug.

How about just

diff --git a/tests/pm_backlight.c b/tests/pm_backlight.c
index 32808cdf6ca4..702ee046d5cb 100644
--- a/tests/pm_backlight.c
+++ b/tests/pm_backlight.c
@@ -177,9 +177,6 @@ test_fade_with_suspend(struct context *context, igt_output_t *output)
 {
 	igt_require(igt_setup_runtime_pm());
 
-	kmstest_set_connector_dpms(output->display->drm_fd,
-				   output->config.connector,
-				   DRM_MODE_DPMS_OFF);
 	igt_require(igt_wait_for_pm_status(IGT_RUNTIME_PM_STATUS_SUSPENDED));
 
 	igt_system_suspend_autoresume(SUSPEND_STATE_MEM, SUSPEND_TEST_NONE);




-- 
Jani Nikula, Intel Open Source Graphics Center