[igt-dev] [RFC i-g-t 1/1] i915/pm_backlight: turn on dpms before backlight fade out and fade in

[Harish Chegondi]

backlight fade with suspend test turns off dpms which turns off
the edp backlight and panel. Then it does a runtime suspend,
system suspend and resume. After resume, it does a fade out and
fade in of the backlight brightness. From the dmesg logs of the
ci tests it appears that the test is setting the brightness
even before the edp panel and backlight are turned on resuilting
in the brightness values written and read to be different.
Turn on the dpms which turns on the edp panel and backlight
before backlight fade out and fade in. With this change the
fade_with_suspend test passes.

Cc: Jyoti Yadav <jyoti.r.yadav at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Clinton Taylor <clinton.a.taylor at intel.com>
Signed-off-by: Harish Chegondi <harish.chegondi at intel.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=107820
---
 tests/i915/i915_pm_backlight.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tests/i915/i915_pm_backlight.c b/tests/i915/i915_pm_backlight.c
index 054300f6..ca640eca 100644
--- a/tests/i915/i915_pm_backlight.c
+++ b/tests/i915/i915_pm_backlight.c
@@ -184,6 +184,9 @@ test_fade_with_suspend(struct context *context, igt_output_t *output)
 
 	igt_system_suspend_autoresume(SUSPEND_STATE_MEM, SUSPEND_TEST_NONE);
 
+	kmstest_set_connector_dpms(output->display->drm_fd,
+				   output->config.connector,
+				   DRM_MODE_DPMS_ON);
 	test_fade(context);
 }
 
-- 
2.20.1