[PATCH i-g-t v8 1/4] lib/igt_kms: Add support to retrieve async modifiers and formats

[Ville Syrjälä]

On Wed, Mar 26, 2025 at 03:57:55PM +0530, Santhosh Reddy Guddati wrote:
> Parse "IN_FORMATS_ASYNC" plane property to identify supported
> format modifier pairs for async flips
> 
> V2: Add new fields async_formats and reset idx.
> 
> V3: Improve commit message , remove unused declaration (Chaitanya)
>     Introduce structure to hold a format modifier and its
>     associated format list.
> 
> V4: Implement format+modifier tuples for async similar to IN_FORMATS
>     (Chaitanya).
> 
> V5: Re use local variables for async formats and free blob after
>     usage(Chaitanya)
> 
> V6: Initialize async_modifiers and async_formats to NULL. (Chaitanya)
> 
> V7: Fix async format count to return 0 on failures (Chaitanya)
> 
> Signed-off-by: Santhosh Reddy Guddati <santhosh.reddy.guddati at intel.com>
> Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.borah at intel.com>
> ---
>  lib/igt_kms.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++--
>  lib/igt_kms.h |  7 ++++++-
>  2 files changed, 60 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/igt_kms.c b/lib/igt_kms.c
> index cc3bb3ae7..c6c3f1894 100644
> --- a/lib/igt_kms.c
> +++ b/lib/igt_kms.c
> @@ -701,6 +701,7 @@ const char * const igt_plane_prop_names[IGT_NUM_PLANE_PROPS] = {
>  	[IGT_PLANE_FB_DAMAGE_CLIPS] = "FB_DAMAGE_CLIPS",
>  	[IGT_PLANE_SCALING_FILTER] = "SCALING_FILTER",
>  	[IGT_PLANE_SIZE_HINTS] = "SIZE_HINTS",
> +	[IGT_PLANE_IN_FORMATS_ASYNC] = "IN_FORMATS_ASYNC",
>  };
>  
>  const char * const igt_crtc_prop_names[IGT_NUM_CRTC_PROPS] = {
> @@ -5759,10 +5760,12 @@ static int igt_count_plane_format_mod(const struct drm_format_modifier_blob *blo
>  static void igt_fill_plane_format_mod(igt_display_t *display, igt_plane_t *plane)
>  {
>  	const struct drm_format_modifier_blob *blob_data;
> +	const struct drm_format_modifier *async_modifiers = NULL;
>  	drmModePropertyBlobPtr blob;
>  	uint64_t blob_id;
>  	int idx = 0;
> -	int count;
> +	int count = 0;
> +	const uint32_t *async_formats = NULL;
>  
>  	if (!igt_plane_has_prop(plane, IGT_PLANE_IN_FORMATS)) {
>  		drmModePlanePtr p = plane->drm_plane;
> @@ -5796,8 +5799,10 @@ static void igt_fill_plane_format_mod(igt_display_t *display, igt_plane_t *plane
>  	blob_data = (const struct drm_format_modifier_blob *) blob->data;
>  
>  	count = igt_count_plane_format_mod(blob_data);
> -	if (!count)
> +	if (!count) {
> +		drmModeFreePropertyBlob(blob);
>  		return;
> +	}
>  
>  	plane->format_mod_count = count;
>  	plane->formats = calloc(count, sizeof(plane->formats[0]));
> @@ -5822,6 +5827,53 @@ static void igt_fill_plane_format_mod(igt_display_t *display, igt_plane_t *plane
>  	}
>  
>  	igt_assert_eq(idx, plane->format_mod_count);
> +
> +	drmModeFreePropertyBlob(blob);
> +
> +	if (!igt_plane_has_prop(plane, IGT_PLANE_IN_FORMATS_ASYNC))
> +		return;
> +
> +	blob_id = igt_plane_get_prop(plane, IGT_PLANE_IN_FORMATS_ASYNC);
> +	blob = drmModeGetPropertyBlob(display->drm_fd, blob_id);
> +
> +	if (!blob)
> +		return;
> +
> +	blob_data = (const struct drm_format_modifier_blob *)blob->data;
> +	count = igt_count_plane_format_mod(blob_data);
> +
> +	if (!count) {
> +		plane->async_format_mod_count = 0;
> +		drmModeFreePropertyBlob(blob);
> +		return;
> +	}
> +
> +	plane->async_format_mod_count = count;
> +	plane->async_modifiers = calloc(count, sizeof(plane->async_modifiers[0]));
> +	igt_assert(plane->async_modifiers);
> +
> +	plane->async_formats = calloc(count, sizeof(plane->async_formats[0]));
> +	igt_assert(plane->async_formats);
> +
> +	idx = 0;
> +	for (int i = 0; i < blob_data->count_modifiers; i++) {
> +		for (int j = 0; j < 64; j++) {
> +			async_modifiers = modifiers_ptr(blob_data);
> +			async_formats = formats_ptr(blob_data);
> +
> +			if (!(async_modifiers[i].formats & (1ULL << j)))
> +				continue;
> +
> +			plane->async_formats[idx] = async_formats[async_modifiers[i].offset + j];
> +			plane->async_modifiers[idx] = async_modifiers[i].modifier;
> +			idx++;
> +			igt_assert_lte(idx, plane->async_format_mod_count);
> +		}
> +	}
> +
> +	igt_assert_eq(idx, plane->async_format_mod_count);
> +
> +	drmModeFreePropertyBlob(blob);

This code looks identical to the existing stuff that parses the normal
blob. Can you refactor that into a common function?

>  }
>  
>  /**
> diff --git a/lib/igt_kms.h b/lib/igt_kms.h
> index 27b545f52..78d6a7ee4 100644
> --- a/lib/igt_kms.h
> +++ b/lib/igt_kms.h
> @@ -365,7 +365,8 @@ enum igt_atomic_plane_properties {
>         IGT_PLANE_HOTSPOT_X,
>         IGT_PLANE_HOTSPOT_Y,
>         IGT_PLANE_SIZE_HINTS,
> -       IGT_NUM_PLANE_PROPS
> +       IGT_PLANE_IN_FORMATS_ASYNC,
> +       IGT_NUM_PLANE_PROPS,
>  };
>  
>  /**
> @@ -438,6 +439,10 @@ typedef struct igt_plane {
>  	uint64_t *modifiers;
>  	uint32_t *formats;
>  	int format_mod_count;
> +
> +	uint64_t *async_modifiers;
> +	uint32_t *async_formats;
> +	int async_format_mod_count;
>  } igt_plane_t;
>  
>  /*
> -- 
> 2.34.1

-- 
Ville Syrjälä
Intel