[igt-dev] [RFC PATCH 1/2] tests/kms_vrr: Use atomic API for page flip

[Manasi Navare]

On Mon, May 11, 2020 at 11:56:46AM +0530, bhanuprakash.modem at intel.com wrote:
> From: Bhanuprakash Modem <bhanuprakash.modem at intel.com>
> 
> We should avoid using drmModePageFlip as it'll only be used for
> legacy drivers, instead, use igt_display_commit_atomic() API to
> page flip for atomic display code path.
> 
> Cc: Harry Wentland <harry.wentland at amd.com>
> Cc: Nicholas Kazlauskas <nicholas.kazlauskas at amd.com>
> Cc: Manasi Navare <manasi.d.navare at intel.com>
> Signed-off-by: Bhanuprakash Modem <bhanuprakash.modem at intel.com>

I have tested this on i915 and the page flips are captured correctly with 
non blocking page flip requests using atomic_commit call.

@Harry, @Nicholas could you test this on AMD driver to make
sure its not breaking anything?

Manasi

> ---
>  tests/kms_vrr.c | 39 ++++++++++-----------------------------
>  1 file changed, 10 insertions(+), 29 deletions(-)
> 
> diff --git a/tests/kms_vrr.c b/tests/kms_vrr.c
> index 73115fef..0fe28931 100644
> --- a/tests/kms_vrr.c
> +++ b/tests/kms_vrr.c
> @@ -126,11 +126,11 @@ static range_t get_vrr_range(data_t *data, igt_output_t *output)
>  }
>  
>  /* Returns a suitable vrr test frequency. */
> -static uint32_t get_test_rate_ns(data_t *data, igt_output_t *output)
> +static uint64_t get_test_rate_ns(data_t *data, igt_output_t *output)
>  {
>  	drmModeModeInfo *mode = igt_output_get_mode(output);
>  	range_t range;
> -	uint32_t vtest;
> +	uint64_t vtest;
>  
>  	/*
>  	 * The frequency with the fastest convergence speed should be
> @@ -210,32 +210,18 @@ wait_for_vblank(data_t *data, enum pipe pipe)
>  	return get_vblank_event_ns(data);
>  }
>  
> -/* Performs an asynchronous non-blocking page-flip on a pipe. */
> -static int
> +/* Performs an atomic non-blocking page-flip on a pipe. */
> +static void
>  do_flip(data_t *data, enum pipe pipe_id, igt_fb_t *fb)
>  {
> -	igt_pipe_t *pipe = &data->display.pipes[pipe_id];
> -	int ret;
> -
>  	igt_set_timeout(1, "Scheduling page flip\n");
>  
> -	/*
> -	 * Only the legacy flip ioctl supports async flips.
> -	 * It's also non-blocking, but returns -EBUSY if flipping too fast.
> -	 * 2x monitor tests will need async flips in the atomic API.
> -	 */
> -	do {
> -		ret = drmModePageFlip(data->drm_fd, pipe->crtc_id,
> -				      fb->fb_id,
> -				      DRM_MODE_PAGE_FLIP_EVENT |
> -				      DRM_MODE_PAGE_FLIP_ASYNC,
> -				      data);
> -	} while (ret == -EBUSY);
> -
> -	igt_assert_eq(ret, 0);
> -	igt_reset_timeout();
> +	igt_display_commit_atomic(&data->display,
> +				  DRM_MODE_ATOMIC_NONBLOCK |
> +				  DRM_MODE_PAGE_FLIP_EVENT,
> +				  NULL);
>  
> -	return 0;
> +	igt_reset_timeout();
>  }
>  
>  /*
> @@ -246,11 +232,6 @@ do_flip(data_t *data, enum pipe pipe_id, igt_fb_t *fb)
>   * can arbitrarily restrict the bounds further than the absolute
>   * min and max range. But VRR is really about extending the flip
>   * to prevent stuttering or to match a source content rate.
> - *
> - * The only way to "present" at a fixed rate like userspace in a vendor
> - * neutral manner is to do it with async flips. This avoids the need
> - * to wait for next vblank and it should eventually converge at the
> - * desired rate.
>   */
>  static uint32_t
>  flip_and_measure(data_t *data, igt_output_t *output, enum pipe pipe,
> @@ -271,7 +252,7 @@ flip_and_measure(data_t *data, igt_output_t *output, enum pipe pipe,
>  		front = !front;
>  		do_flip(data, pipe, front ? &data->fb1 : &data->fb0);
>  
> -		vblank_ns = get_vblank_event_ns(data);
> +		vblank_ns = wait_for_vblank(data, pipe);
>  		diff_ns = rate_ns - (vblank_ns - last_vblank_ns);
>  		last_vblank_ns = vblank_ns;
>  
> -- 
> 2.24.1.1.gb6d4d82bd5
>