[PATCH v2 04/16] drm/i915/mst: change return value of mst_stream_find_vcpi_slots_for_bpp()

[Imre Deak]

On Thu, Dec 19, 2024 at 11:33:53PM +0200, Jani Nikula wrote:
> The callers of mst_stream_find_vcpi_slots_for_bpp() don't need the
> returned slots for anything. On the contrary, they need to jump through
> hoops to just distinguish between success and failure. Just return 0
> instead of slots from mst_stream_find_vcpi_slots_for_bpp() for success,
> and simplify the callers.
> 
> There's a pointless ret local variable that we can drop in the process.
> 
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>

Reviewed-by: Imre Deak <imre.deak at intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_dp_mst.c | 52 +++++++--------------
>  1 file changed, 18 insertions(+), 34 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index f52f9c968adb..f7b91cf32b5b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -226,7 +226,6 @@ static int mst_stream_find_vcpi_slots_for_bpp(struct intel_dp *intel_dp,
>  	int bpp, slots = -EINVAL;
>  	int dsc_slice_count = 0;
>  	int max_dpt_bpp;
> -	int ret = 0;
>  
>  	mst_state = drm_atomic_get_mst_topology_state(state, &intel_dp->mst_mgr);
>  	if (IS_ERR(mst_state))
> @@ -340,23 +339,21 @@ static int mst_stream_find_vcpi_slots_for_bpp(struct intel_dp *intel_dp,
>  		}
>  	}
>  
> -	/* We failed to find a proper bpp/timeslots, return error */
> -	if (ret)
> -		slots = ret;
> -
>  	if (slots < 0) {
>  		drm_dbg_kms(display->drm, "failed finding vcpi slots:%d\n",
>  			    slots);
> -	} else {
> -		if (!dsc)
> -			crtc_state->pipe_bpp = bpp;
> -		else
> -			crtc_state->dsc.compressed_bpp_x16 = fxp_q4_from_int(bpp);
> -		drm_dbg_kms(display->drm, "Got %d slots for pipe bpp %d dsc %d\n",
> -			    slots, bpp, dsc);
> +		return slots;
>  	}
>  
> -	return slots;
> +	if (!dsc)
> +		crtc_state->pipe_bpp = bpp;
> +	else
> +		crtc_state->dsc.compressed_bpp_x16 = fxp_q4_from_int(bpp);
> +
> +	drm_dbg_kms(display->drm, "Got %d slots for pipe bpp %d dsc %d\n",
> +		    slots, bpp, dsc);
> +
> +	return 0;
>  }
>  
>  static int mst_stream_compute_link_config(struct intel_dp *intel_dp,
> @@ -364,22 +361,15 @@ static int mst_stream_compute_link_config(struct intel_dp *intel_dp,
>  					  struct drm_connector_state *conn_state,
>  					  struct link_config_limits *limits)
>  {
> -	int slots = -EINVAL;
> -
>  	/*
>  	 * FIXME: allocate the BW according to link_bpp, which in the case of
>  	 * YUV420 is only half of the pipe bpp value.
>  	 */
> -	slots = mst_stream_find_vcpi_slots_for_bpp(intel_dp, crtc_state,
> -						   fxp_q4_to_int(limits->link.max_bpp_x16),
> -						   fxp_q4_to_int(limits->link.min_bpp_x16),
> -						   limits,
> -						   conn_state, 2 * 3, false);
> -
> -	if (slots < 0)
> -		return slots;
> -
> -	return 0;
> +	return mst_stream_find_vcpi_slots_for_bpp(intel_dp, crtc_state,
> +						  fxp_q4_to_int(limits->link.max_bpp_x16),
> +						  fxp_q4_to_int(limits->link.min_bpp_x16),
> +						  limits,
> +						  conn_state, 2 * 3, false);
>  }
>  
>  static int mst_stream_dsc_compute_link_config(struct intel_dp *intel_dp,
> @@ -389,7 +379,6 @@ static int mst_stream_dsc_compute_link_config(struct intel_dp *intel_dp,
>  {
>  	struct intel_display *display = to_intel_display(intel_dp);
>  	struct intel_connector *connector = to_intel_connector(conn_state->connector);
> -	int slots = -EINVAL;
>  	int i, num_bpc;
>  	u8 dsc_bpc[3] = {};
>  	int min_bpp, max_bpp, sink_min_bpp, sink_max_bpp;
> @@ -451,14 +440,9 @@ static int mst_stream_dsc_compute_link_config(struct intel_dp *intel_dp,
>  	min_compressed_bpp = intel_dp_dsc_nearest_valid_bpp(display, min_compressed_bpp,
>  							    crtc_state->pipe_bpp);
>  
> -	slots = mst_stream_find_vcpi_slots_for_bpp(intel_dp, crtc_state, max_compressed_bpp,
> -						   min_compressed_bpp, limits,
> -						   conn_state, 1, true);
> -
> -	if (slots < 0)
> -		return slots;
> -
> -	return 0;
> +	return mst_stream_find_vcpi_slots_for_bpp(intel_dp, crtc_state, max_compressed_bpp,
> +						  min_compressed_bpp, limits,
> +						  conn_state, 1, true);
>  }
>  
>  static int mst_stream_update_slots(struct intel_dp *intel_dp,
> -- 
> 2.39.5
>