Re: [Intel-gfx] [PATCH v6 6/9] drm/i915/vdsc: Check slice design requirement

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 11 Jan 2023, Suraj Kandpal <suraj.kandpal@intel.com> wrote:
> Add function to check if slice design requirements are being
> met as defined in the below link section Slice Design Requirement
>
> https://gfxspecs.intel.com/Predator/Home/Index/49259
>

Just add this:

Bspec: 49259

and no URLs.

> Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_vdsc.c | 32 +++++++++++++++++++++++
>  1 file changed, 32 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c b/drivers/gpu/drm/i915/display/intel_vdsc.c
> index 52a82d8b289e..0a683d6dff33 100644
> --- a/drivers/gpu/drm/i915/display/intel_vdsc.c
> +++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
> @@ -447,6 +447,29 @@ calculate_rc_params(struct rc_parameters *rc,
>  	}
>  }
>  
> +static int intel_dsc_check_slice_design_req(struct intel_crtc_state *pipe_config,
> +					    struct drm_dsc_config *vdsc_cfg)

Bikeshedding, I think "check" is generally a poor verb in a function
name.

intel_dsc_slice_dimensions_valid() or something like that?


> +{
> +	if (pipe_config->output_format == INTEL_OUTPUT_FORMAT_RGB ||
> +	    pipe_config->output_format == INTEL_OUTPUT_FORMAT_YCBCR444) {
> +		if (vdsc_cfg->slice_height > 4095)
> +			return -EINVAL;
> +		if (vdsc_cfg->slice_height * vdsc_cfg->slice_width < 15000)
> +			return -EINVAL;
> +	} else if (pipe_config->output_format == INTEL_OUTPUT_FORMAT_YCBCR420) {
> +		if (!(vdsc_cfg->slice_width % 2))
> +			return -EINVAL;
> +		if (!(vdsc_cfg->slice_height % 2))
> +			return -EINVAL;
> +		if (vdsc_cfg->slice_height > 4094)
> +			return -EINVAL;
> +		if (vdsc_cfg->slice_height * vdsc_cfg->slice_width < 30000)
> +			return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
>  int intel_dsc_compute_params(struct intel_crtc_state *pipe_config)
>  {
>  	struct intel_crtc *crtc = to_intel_crtc(pipe_config->uapi.crtc);
> @@ -455,11 +478,20 @@ int intel_dsc_compute_params(struct intel_crtc_state *pipe_config)
>  	u16 compressed_bpp = pipe_config->dsc.compressed_bpp;
>  	const struct rc_parameters *rc_params;
>  	struct rc_parameters *rc = NULL;
> +	int err;
>  	u8 i = 0;
>  
>  	vdsc_cfg->pic_width = pipe_config->hw.adjusted_mode.crtc_hdisplay;
>  	vdsc_cfg->slice_width = DIV_ROUND_UP(vdsc_cfg->pic_width,
>  					     pipe_config->dsc.slice_count);
> +
> +	err = intel_dsc_check_slice_design_req(pipe_config, vdsc_cfg);
> +
> +	if (err) {
> +		drm_dbg_kms(&dev_priv->drm, "Slice design requirements not met\n");
> +		return err;
> +	}
> +
>  	/*
>  	 * According to DSC 1.2 specs if colorspace is YCbCr then convert_rgb is 0
>  	 * else 1

-- 
Jani Nikula, Intel Open Source Graphics Center