[igt-dev] [PATCH i-g-t 5/6] lib/i915: Add ADL-P stride restrictions for non-linear buffers

[Souza, Jose]

Hum we can drop this change, Imre landed changes to make framebuffers strides power of two for adl_p, so for userspace it should be transparent.

On Fri, 2021-06-04 at 13:39 -0700, Matt Roper wrote:
> From: José Roberto de Souza <jose.souza at intel.com>
> 
> ADL-P tiled framebuffer strides must be power-of-two aligned and has a
> minimum of 8 tiles. For non-CCS framebuffers the driver supports FBs not
> meeting this requirement by remapping the framebuffer and padding the
> stride as required, but for CCS FBs userspace must ensure the alignment.
> Adding remap support for CCS FBs to the driver is to be done as a
> follow-up.
> 
> Cc: Juha-Pekka Heikkilä <juha-pekka.heikkila at intel.com>
> Cc: Anusha Srivatsa <anusha.srivatsa at intel.com>
> Cc: Clinton Taylor <Clinton.A.Taylor at intel.com>
> Cc: Stanislav Lisovskiy <stanislav.lisovskiy at intel.com>
> Cc: Imre Deak <imre.deak at intel.com>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
> ---
>  lib/igt_fb.c | 26 +++++++++++++++++++++-----
>  1 file changed, 21 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/igt_fb.c b/lib/igt_fb.c
> index 585ede38..ce2aa6ce 100644
> --- a/lib/igt_fb.c
> +++ b/lib/igt_fb.c
> @@ -729,8 +729,16 @@ static uint32_t calc_plane_stride(struct igt_fb *fb, int plane)
>  		/* clear color always fixed to 64 bytes */
>  		return 64;
>  	} else if (is_gen12_ccs_plane(fb, plane)) {
> -		/* A main surface using a CCS AUX surface must be 4x4 tiles aligned. */
> -		return ALIGN(min_stride, 64);
> +		/*
> +		 * A main surface using a CCS AUX surface must be 4x4 tiles
> +		 * aligned.  On ADL_P the minimum main surface stride is 8
> +		 * tiles (2 * 64 byte on CCS surface) and it has to be POT
> +		 * aligned.
> +		 */
> +		if (IS_ALDERLAKE_P(intel_get_drm_devid(fb->fd)))
> +			return roundup_power_of_two(max(min_stride, 128u));
> +		else
> +			return ALIGN(min_stride, 64);
>  	} else if (!fb->modifier && is_nouveau_device(fb->fd)) {
>  		int align;
>  
> @@ -743,14 +751,22 @@ static uint32_t calc_plane_stride(struct igt_fb *fb, int plane)
>  		return ALIGN(min_stride, align);
>  	} else {
>  		unsigned int tile_width, tile_height;
> +		uint32_t stride;
>  
>  		igt_get_fb_tile_size(fb->fd, fb->modifier, fb->plane_bpp[plane],
>  				     &tile_width, &tile_height);
>  
> -		if (is_gen12_ccs_modifier(fb->modifier))
> -			tile_width *= 4;
> +		if (is_gen12_ccs_modifier(fb->modifier)) {
> +			stride = ALIGN(min_stride, tile_width * 4);
>  
> -		return ALIGN(min_stride, tile_width);
> +			/* TODO: add support to kernel to POT align CCS format strides */
> +			if (IS_ALDERLAKE_P(intel_get_drm_devid(fb->fd)))
> +				stride = roundup_power_of_two(max(stride, tile_width * 8));
> +		} else {
> +			stride = ALIGN(min_stride, tile_width);
> +		}
> +
> +		return stride;
>  	}
>  }
>