[igt-dev] [PATCH i-g-t v5] tests/kms_plane_scaling: Increase buffer size if driver doesn't support larger scale factors

[Petri Latvala]

On Tue, Jan 25, 2022 at 05:01:05PM -0800, Jessica Zhang wrote:
> Catch edge cases where driver doesn't support larger scale factors or
> pipe doesn't support scaling.
> 
> Currently, a 20x20 framebuffer is passed in to be upscaled. However,
> this will cause issues with other drivers as they may not support larger
> scale factors or may not support scaling at all for certain planes.
> 
> This avoids failures due to invalid scale factor by trying
> the original 20x20 framebuffer commit, then trying to commit larger
> framebuffers up to and including unity scale.
> 
> Changes since V1:
> - try_commit_with_fb_size: Changed igt_try_commit2 to
>   igt_display_try_commit_atomic instead to avoid redundant commits
> - try_commit_with_fb_size: Moved calls to clear framebuffer to outside
>   of success condition and moved cleanup_crtc back to outside of method
> 
> Changes since V2:
> - try_commit_with_fb_size: Replaced igt_display_try_commit_atomic with
>   igt_display_try_commit2 and removed igt_display_try_commit2 to avoid
>   redundant checks
> 
> Changes since V3:
> - try_commit_with_fb_size: Moved igt_plane_set_position to outside
>   method after fallback cases
> 
> Changes since V4:
> - try_commit_with_fb_size: Moved igt_create_color_fb to inside
>   display_try_commit_with_fb and moved igt_set_plane_fb out so that a
>   new framebuffer is created and set for different sizes
> 
> Tested-on: Qualcomm RB5 (sdm845), Chromebook (Lazor)
> 
> Signed-off-by: Jessica Zhang <quic_jesszhan at quicinc.com>
> Change-Id: Ib6758fec0293a2ba4c4109fbf42674cf93f784dd
> ---
>  tests/kms_plane_scaling.c | 57 +++++++++++++++++++++++++++++++--------
>  1 file changed, 46 insertions(+), 11 deletions(-)
> 
> diff --git a/tests/kms_plane_scaling.c b/tests/kms_plane_scaling.c
> index 85db11ee6dbd..bbc89c23b91f 100644
> --- a/tests/kms_plane_scaling.c
> +++ b/tests/kms_plane_scaling.c
> @@ -1,5 +1,6 @@
>  /*
>   * Copyright © 2013,2014 Intel Corporation
> + * Copyright (c) 2021-2022 Qualcomm Innovation Center, Inc. All rights reserved.
>   *
>   * Permission is hereby granted, free of charge, to any person obtaining a
>   * copy of this software and associated documentation files (the "Software"),
> @@ -118,6 +119,32 @@ static void prepare_crtc(data_t *data, igt_output_t *output, enum pipe pipe,
>  	igt_display_commit2(display, COMMIT_ATOMIC);
>  }
>  
> +static int try_commit_with_fb_size(int width, int height, igt_rotation_t rot,
> +				   igt_display_t *display, data_t *d,
> +				   uint32_t pixel_format,
> +				   uint64_t modifier,
> +				   igt_plane_t *plane,
> +				   drmModeModeInfo *mode)
> +{
> +	int ret;
> +
> +	/* create buffer in the range of  min and max source side limit.*/
> +	igt_create_color_fb(display->drm_fd, width, height,
> +		       pixel_format, modifier, 0.0, 1.0, 0.0, &d->fb[0]);
> +	igt_plane_set_fb(plane, &d->fb[0]);
> +
> +	/* Check min to full resolution upscaling */
> +	igt_fb_set_position(&d->fb[0], plane, 0, 0);
> +	igt_fb_set_size(&d->fb[0], plane, width, height);
> +	igt_plane_set_position(plane, 0, 0);
> +	igt_plane_set_size(plane, mode->hdisplay, mode->vdisplay);
> +	igt_plane_set_rotation(plane, rot);
> +
> +	ret = igt_display_try_commit2(display, COMMIT_ATOMIC);
> +
> +	return ret;
> +}
> +
>  static void check_scaling_pipe_plane_rot(data_t *d, igt_plane_t *plane,
>  					 uint32_t pixel_format,
>  					 uint64_t modifier, enum pipe pipe,
> @@ -126,6 +153,7 @@ static void check_scaling_pipe_plane_rot(data_t *d, igt_plane_t *plane,
>  {
>  	igt_display_t *display = &d->display;
>  	int width, height;
> +	int commit_ret;
>  	drmModeModeInfo *mode;
>  
>  	cleanup_crtc(d);
> @@ -133,22 +161,29 @@ static void check_scaling_pipe_plane_rot(data_t *d, igt_plane_t *plane,
>  	igt_output_set_pipe(output, pipe);
>  	mode = igt_output_get_mode(output);
>  
> -	/* create buffer in the range of  min and max source side limit.*/
>  	width = height = 20;
> -	igt_create_color_fb(display->drm_fd, width, height,
> -		       pixel_format, modifier, 0.0, 1.0, 0.0, &d->fb[0]);
> -	igt_plane_set_fb(plane, &d->fb[0]);
>  
> -	/* Check min to full resolution upscaling */
> -	igt_fb_set_position(&d->fb[0], plane, 0, 0);
> -	igt_fb_set_size(&d->fb[0], plane, width, height);
> -	igt_plane_set_position(plane, 0, 0);
> -	igt_plane_set_size(plane, mode->hdisplay, mode->vdisplay);
> -	igt_plane_set_rotation(plane, rot);
> -	igt_display_commit2(display, COMMIT_ATOMIC);
> +	commit_ret = try_commit_with_fb_size(width, height, rot, display, d,
> +					     pixel_format, modifier, plane, mode);
> +
> +	if(commit_ret == -ERANGE) {
> +		igt_debug("Scaling for %dx%d plane not supported, trying scale factor of 4x\n", width, height);
> +		width = height = mode->vdisplay / 4;
> +		commit_ret = try_commit_with_fb_size(width, height, rot, display, d,
> +						     pixel_format, modifier, plane, mode);
> +	}
> +
> +	if (commit_ret == -ERANGE) {
> +		igt_debug("Scale factor of 4x (or scaling in general) not supported, trying unity scale\n");
> +		width = mode->hdisplay;
> +		height = mode->vdisplay;
> +		commit_ret = try_commit_with_fb_size(width, height, rot, display, d,
> +						     pixel_format, modifier, plane, mode);
> +	}

Now the changes look good and they do what it says on the tin. But now
it got me thinking if this needs to be even more complicated...

If a kernel change causes the first scaling attempt to fail and this
goes into the fallbacks and succeeds there, it all happens very
silently. A better setup for catching that case would be to have
separate dynamic subtests for the different scaling factors, where the
unsupported factors do a 'SKIP' result with igt_skip_on_f(commit_ret
== -ERANGE, "Unsupported scaling factor\n");

What do you think? Sorry to go back and forth like this on the patch.


-- 
Petri Latvala



>  
>  	igt_plane_set_fb(plane, NULL);
>  	igt_plane_set_position(plane, 0, 0);
> +	igt_assert_eq(commit_ret, 0);
>  }
>  
>  static const igt_rotation_t rotations[] = {
> -- 
> 2.31.0
>