drm/i915/dsc: Switch to using intel_dsc_line_slice_count()

By now all the places are updated to track the DSC slice configuration
in intel_crtc_state::dsc.slice_config, so calculate the slices-per-line
value using that config, instead of using
intel_crtc_state::dsc.slice_count caching the same value and remove
the cached slice_count.

v2: Rebase on latest drm-tip, converting another user of dsc.slice_count
    in intel_vdsc_min_cdclk().

Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Jouni Högander <jouni.hogander@intel.com> # v1
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260114162232.92731-7-imre.deak@intel.com

4 files changed, 12 insertions, 15 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index 8fcfdb2e1c74..a007fcf6e1a8 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -3597,14 +3597,12 @@ static void fill_dsc(struct intel_crtc_state *crtc_state,
 		crtc_state->dsc.slice_config.slices_per_stream = 1;
 	}
 
-	crtc_state->dsc.slice_count = intel_dsc_line_slice_count(&crtc_state->dsc.slice_config);
-
 	if (crtc_state->hw.adjusted_mode.crtc_hdisplay %
-	    crtc_state->dsc.slice_count != 0)
+	    intel_dsc_line_slice_count(&crtc_state->dsc.slice_config) != 0)
 		drm_dbg_kms(display->drm,
 			    "VBT: DSC hdisplay %d not divisible by slice count %d\n",
 			    crtc_state->hw.adjusted_mode.crtc_hdisplay,
-			    crtc_state->dsc.slice_count);
+			    intel_dsc_line_slice_count(&crtc_state->dsc.slice_config));
 
 	/*
 	 * The VBT rc_buffer_block_size and rc_buffer_size definitions
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index f223cabb185a..c7a8e475cb22 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1339,7 +1339,6 @@ struct intel_crtc_state {
 		} slice_config;
 		/* Compressed Bpp in U6.4 format (first 4 bits for fractional part) */
 		u16 compressed_bpp_x16;
-		u8 slice_count;
 		struct drm_dsc_config config;
 	} dsc;
 
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 3b62d16403f2..3a12156cd6e5 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -2032,12 +2032,14 @@ static int dsc_compute_link_config(struct intel_dp *intel_dp,
 			} else {
 				unsigned long bw_overhead_flags =
 					pipe_config->fec_enable ? DRM_DP_BW_OVERHEAD_FEC : 0;
+				int line_slice_count =
+					intel_dsc_line_slice_count(&pipe_config->dsc.slice_config);
 
 				if (!is_bw_sufficient_for_dsc_config(intel_dp,
 								     link_rate, lane_count,
 								     adjusted_mode->crtc_clock,
 								     adjusted_mode->hdisplay,
-								     pipe_config->dsc.slice_count,
+								     line_slice_count,
 								     dsc_bpp_x16,
 								     bw_overhead_flags))
 					continue;
@@ -2428,11 +2430,8 @@ int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
 		pipe_config->dsc.slice_config.pipes_per_line /
 		pipe_config->dsc.slice_config.streams_per_pipe;
 
-	pipe_config->dsc.slice_count =
-		intel_dsc_line_slice_count(&pipe_config->dsc.slice_config);
-
 	drm_WARN_ON(display->drm,
-		    pipe_config->dsc.slice_count != slices_per_line);
+		    intel_dsc_line_slice_count(&pipe_config->dsc.slice_config) != slices_per_line);
 
 	ret = intel_dp_dsc_compute_params(connector, pipe_config);
 	if (ret < 0) {
@@ -2450,7 +2449,7 @@ int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
 		    "Compressed Bpp = " FXP_Q4_FMT " Slice Count = %d\n",
 		    pipe_config->pipe_bpp,
 		    FXP_Q4_ARGS(pipe_config->dsc.compressed_bpp_x16),
-		    pipe_config->dsc.slice_count);
+		    intel_dsc_line_slice_count(&pipe_config->dsc.slice_config));
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c b/drivers/gpu/drm/i915/display/intel_vdsc.c
index 4a3d505338cb..d213947103b5 100644
--- a/drivers/gpu/drm/i915/display/intel_vdsc.c
+++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
@@ -283,8 +283,9 @@ int intel_dsc_compute_params(struct intel_crtc_state *pipe_config)
 	int ret;
 
 	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);
+	vdsc_cfg->slice_width =
+		DIV_ROUND_UP(vdsc_cfg->pic_width,
+			     intel_dsc_line_slice_count(&pipe_config->dsc.slice_config));
 
 	err = intel_dsc_slice_dimensions_valid(pipe_config, vdsc_cfg);
 
@@ -1042,7 +1043,7 @@ static void intel_vdsc_dump_state(struct drm_printer *p, int indent,
 	drm_printf_indent(p, indent,
 			  "dsc-dss: compressed-bpp:" FXP_Q4_FMT ", slice-count: %d, num_streams: %d\n",
 			  FXP_Q4_ARGS(crtc_state->dsc.compressed_bpp_x16),
-			  crtc_state->dsc.slice_count,
+			  intel_dsc_line_slice_count(&crtc_state->dsc.slice_config),
 			  crtc_state->dsc.slice_config.streams_per_pipe);
 }
 
@@ -1078,7 +1079,7 @@ int intel_vdsc_min_cdclk(const struct intel_crtc_state *crtc_state)
 	struct intel_display *display = to_intel_display(crtc_state);
 	int num_vdsc_instances = intel_dsc_get_num_vdsc_instances(crtc_state);
 	int htotal = crtc_state->hw.adjusted_mode.crtc_htotal;
-	int dsc_slices = crtc_state->dsc.slice_count;
+	int dsc_slices = intel_dsc_line_slice_count(&crtc_state->dsc.slice_config);
 	int pixel_rate;
 	int min_cdclk;