[PATCH 6/7] drm/i915/dp: Use clamp for pipe_bpp limits with DSC

[Kandpal, Suraj]

> -----Original Message-----
> From: Nautiyal, Ankit K <ankit.k.nautiyal at intel.com>
> Sent: Thursday, October 3, 2024 4:14 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: intel-xe at lists.freedesktop.org; Kandpal, Suraj
> <suraj.kandpal at intel.com>; jani.nikula at linux.intel.com
> Subject: [PATCH 6/7] drm/i915/dp: Use clamp for pipe_bpp limits with DSC
> 
> Currently to get the max pipe_bpp with dsc we take the min of
> limits->pipe.max_bpp and dsc max bpp (dsc max bpc * 3). This can result
> in problems when limits->pipe.max_bpp is less than the computed dsc min
> bpp (dsc min bpc * 3).
> 
> Replace the min/max functions with clamp while computing
> limits->pipe.max/min_bpp to ensure that the pipe_bpp limits are
> limits->constrained
> within the DSC-defined minimum and maximum values.
> 

> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>

LGTM,
Reviewed-by: Suraj Kandpal <suraj.kandpal at intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_dp.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index 55ee438a4fec..02009ae03840 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2490,8 +2490,11 @@ intel_dp_compute_config_limits(struct intel_dp
> *intel_dp,
>  		int dsc_min_bpc = intel_dp_dsc_min_src_input_bpc(display);
>  		int dsc_max_bpc =
> intel_dp_dsc_max_src_input_bpc(display);
> 
> -		limits->pipe.max_bpp = min(limits->pipe.max_bpp,
> dsc_max_bpc * 3);
> -		limits->pipe.min_bpp = max(limits->pipe.min_bpp,
> dsc_min_bpc * 3);
> +		limits->pipe.max_bpp = clamp(limits->pipe.max_bpp,
> +					     dsc_min_bpc * 3, dsc_max_bpc *
> 3);
> +
> +		limits->pipe.min_bpp = clamp(limits->pipe.min_bpp,
> +					     dsc_min_bpc * 3, dsc_max_bpc *
> 3);
>  	}
> 
>  	if (intel_dp->use_max_params) {
> --
> 2.45.2