[igt-dev] [PATCH v2 1/1] i915/pm_backlight: Do not turn off DPMS before system suspend

[Daniel Vetter]

On Wed, Apr 03, 2019 at 06:26:30PM -0700, Harish Chegondi wrote:
> backlight fade with suspend test turns off dpms which turns off the edp
> backlight. Then it does a system suspend and resume. After resume,
> the edp backlight would still be off, but the test sets the brightness
> value and reads it back. Since the edp backlight is off, the brightness
> values written and read are different causing the test to fail.
> 
> Do not turn off the DPMS before suspend so that after system resume,
> the edp backlight would be on and setting the brightness value would
> be successful.
> 
> v2: Remove "DPMS off" before system suspend instead of adding
>     "DPMS on" after system resume.
> 
> Cc: Jyoti Yadav <jyoti.r.yadav at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Daniel Vetter <daniel.vetter at intel.com>
> 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
> Fixes: 377752242995 ("Brightness test with DPMS and System suspend.")

I think this makes sense. Still not sure what exactly the test tries to
verify ...

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

> ---
>  tests/i915/i915_pm_backlight.c | 7 -------
>  1 file changed, 7 deletions(-)
> 
> diff --git a/tests/i915/i915_pm_backlight.c b/tests/i915/i915_pm_backlight.c
> index 054300f6..4c1bff5b 100644
> --- a/tests/i915/i915_pm_backlight.c
> +++ b/tests/i915/i915_pm_backlight.c
> @@ -175,13 +175,6 @@ test_fade_with_dpms(struct context *context, igt_output_t *output)
>  static void
>  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);
>  
>  	test_fade(context);
> -- 
> 2.20.1
> 
> _______________________________________________
> igt-dev mailing list
> igt-dev at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/igt-dev

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch