[Intel-gfx] [PATCH i-g-t] kms_atomic_transition: Add subtest time limit/randomize plane, pipe combinations

[Chris Wilson]

Quoting Imre Deak (2017-10-31 13:44:47)
> Doing modeset on internal panels may have a considerable overhead due to
> the panel specific power sequencing delays. To avoid long test runtimes
> limit the runtime of each subtest. Randomize the plane/pipe combinations
> to preserve the test coverage on such panels at least over multiple test
> runs.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103334
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Signed-off-by: Imre Deak <imre.deak at intel.com>
> ---
>  tests/kms_atomic_transition.c | 175 ++++++++++++++++++++++++++++++++++++------
>  1 file changed, 150 insertions(+), 25 deletions(-)
> 
> diff --git a/tests/kms_atomic_transition.c b/tests/kms_atomic_transition.c
> index 4c295125..ac67fc3a 100644
> --- a/tests/kms_atomic_transition.c
> +++ b/tests/kms_atomic_transition.c
> @@ -39,6 +39,14 @@
>  #define DRM_CAP_CURSOR_HEIGHT 0x9
>  #endif
>  
> +#define MAX_SUBTEST_DURATION_NS (20ULL * NSEC_PER_SEC)
> +
> +struct test_config {
> +       igt_display_t *display;
> +       bool user_seed;
> +       int seed;
> +};
> +
>  struct plane_parms {
>         struct igt_fb *fb;
>         uint32_t width, height;
> @@ -401,6 +409,28 @@ static void wait_for_transition(igt_display_t *display, enum pipe pipe, bool non
>         }
>  }
>  
> +/* Copied from https://benpfaff.org/writings/clc/shuffle.html */
> +static void shuffle_array(uint32_t *array, int size, int seed)
> +{
> +       int i;
> +
> +       for (i = 0; i < size; i++) {
> +               int j = i + rand() / (RAND_MAX / (size - i) + 1);
> +
> +               igt_swap(array[i], array[j]);
> +       }
> +}

igt_permute_array()

Not saying anything, but I was told using CI for stochastic coverage was
a flat no...
-Chris