[igt-dev] [PATCH v2 1/2] tests/kms_vrr: Use atomic API for page flip

[Navare, Manasi]

On Thu, Aug 06, 2020 at 12:05:05AM +0530, Bhanuprakash Modem wrote:
> 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.
> 
> v2:
> * Look for the page flip event not for the vblank event (Nicholas)

Where have you done this change to wait for page flip event instead of vblank event?
I thought we would need to change the function get_vblank_event_ns() for this, I dont see
that change below, may be I am missing something?

@Nicholas, have you tested the AMD stack with the page flip event timestamp deltas
instead of the vblank event timetsmap deltas and does that work?

Manasi

> * Fix to flip with different FBs (Bhanu)
> 
> 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>
> ---
>  tests/kms_vrr.c | 45 +++++++++++++++++----------------------------
>  1 file changed, 17 insertions(+), 28 deletions(-)
> 
> diff --git a/tests/kms_vrr.c b/tests/kms_vrr.c
> index 559ef203..b433a12e 100644
> --- a/tests/kms_vrr.c
> +++ b/tests/kms_vrr.c
> @@ -47,6 +47,7 @@ typedef struct range {
>  typedef struct data {
>  	igt_display_t display;
>  	int drm_fd;
> +	igt_plane_t *primary;
>  	igt_fb_t fb0;
>  	igt_fb_t fb1;
>  } data_t;
> @@ -126,11 +127,11 @@ 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
> @@ -165,7 +166,6 @@ static void set_vrr_on_pipe(data_t *data, enum pipe pipe, bool enabled)
>  static void prepare_test(data_t *data, igt_output_t *output, enum pipe pipe)
>  {
>  	drmModeModeInfo mode = *igt_output_get_mode(output);
> -	igt_plane_t *primary;
>  	cairo_t *cr;
>  
>  	/* Reset output */
> @@ -189,8 +189,8 @@ static void prepare_test(data_t *data, igt_output_t *output, enum pipe pipe)
>  	igt_put_cairo_ctx(cr);
>  
>  	/* Take care of any required modesetting before the test begins. */
> -	primary = igt_output_get_plane_type(output, DRM_PLANE_TYPE_PRIMARY);
> -	igt_plane_set_fb(primary, &data->fb0);
> +	data->primary = igt_output_get_plane_type(output, DRM_PLANE_TYPE_PRIMARY);
> +	igt_plane_set_fb(data->primary, &data->fb0);
>  
>  	igt_display_commit_atomic(&data->display,
>  				  DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);
> @@ -210,32 +210,25 @@ 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
> -do_flip(data_t *data, enum pipe pipe_id, igt_fb_t *fb)
> +/* Performs an atomic non-blocking page-flip on a pipe. */
> +static void
> +do_flip(data_t *data, igt_fb_t *fb)
>  {
> -	igt_pipe_t *pipe = &data->display.pipes[pipe_id];
> -	int ret;
> +	int ret = 0;
>  
>  	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.
> -	 */
> +	igt_plane_set_fb(data->primary, fb);
> +
>  	do {
> -		ret = drmModePageFlip(data->drm_fd, pipe->crtc_id,
> -				      fb->fb_id,
> -				      DRM_MODE_PAGE_FLIP_EVENT |
> -				      DRM_MODE_PAGE_FLIP_ASYNC,
> -				      data);
> +		igt_display_commit_atomic(&data->display,
> +				  DRM_MODE_ATOMIC_NONBLOCK |
> +				  DRM_MODE_PAGE_FLIP_EVENT,
> +				  data);
>  	} while (ret == -EBUSY);
>  
>  	igt_assert_eq(ret, 0);
>  	igt_reset_timeout();
> -
> -	return 0;
>  }
>  
>  /*
> @@ -246,11 +239,6 @@ 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,
> @@ -269,7 +257,7 @@ flip_and_measure(data_t *data, igt_output_t *output, enum pipe pipe,
>  		int64_t diff_ns;
>  
>  		front = !front;
> -		do_flip(data, pipe, front ? &data->fb1 : &data->fb0);
> +		do_flip(data, front ? &data->fb1 : &data->fb0);
>  
>  		vblank_ns = get_vblank_event_ns(data);
>  		diff_ns = rate_ns - (vblank_ns - last_vblank_ns);
> @@ -359,6 +347,7 @@ test_basic(data_t *data, enum pipe pipe, igt_output_t *output, uint32_t flags)
>  		     "Target VRR off threshold exceeded, result was %u%%\n",
>  		     result);
>  
> +	igt_plane_set_fb(data->primary, NULL);
>  	igt_remove_fb(data->drm_fd, &data->fb1);
>  	igt_remove_fb(data->drm_fd, &data->fb0);
>  }
> -- 
> 2.20.1
>