drm/i915/dsc: move slice height calculation to encoder

Turns out this isn't compatible with DSI, where we use the value from
VBT. No functional changes.

Cc: Manasi Navare <manasi.d.navare@intel.com>
Cc: Vandita Kulkarni <vandita.kulkarni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/3dd689688a51daff26088eaf6feac27f8b9f5ebc.1575974743.git.jani.nikula@intel.com

drivers/gpu/drm/i915/display/intel_dp.c

@@ -2060,6 +2060,18 @@ static int intel_dp_dsc_compute_params(struct intel_encoder *encoder,
 	if (ret)
 		return ret;
 
+	/*
+	 * Slice Height of 8 works for all currently available panels. So start
+	 * with that if pic_height is an integral multiple of 8. Eventually add
+	 * logic to try multiple slice heights.
+	 */
+	if (vdsc_cfg->pic_height % 8 == 0)
+		vdsc_cfg->slice_height = 8;
+	else if (vdsc_cfg->pic_height % 4 == 0)
+		vdsc_cfg->slice_height = 4;
+	else
+		vdsc_cfg->slice_height = 2;
+
 	vdsc_cfg->dsc_version_major =
 		(intel_dp->dsc_dpcd[DP_DSC_REV - DP_DSC_SUPPORT] &
 		 DP_DSC_MAJOR_MASK) >> DP_DSC_MAJOR_SHIFT;

drivers/gpu/drm/i915/display/intel_vdsc.c

@@ -345,17 +345,6 @@ int intel_dsc_compute_params(struct intel_encoder *encoder,
 	vdsc_cfg->pic_height = pipe_config->hw.adjusted_mode.crtc_vdisplay;
 	vdsc_cfg->slice_width = DIV_ROUND_UP(vdsc_cfg->pic_width,
 					     pipe_config->dsc.slice_count);
-	/*
-	 * Slice Height of 8 works for all currently available panels. So start
-	 * with that if pic_height is an integral multiple of 8.
-	 * Eventually add logic to try multiple slice heights.
-	 */
-	if (vdsc_cfg->pic_height % 8 == 0)
-		vdsc_cfg->slice_height = 8;
-	else if (vdsc_cfg->pic_height % 4 == 0)
-		vdsc_cfg->slice_height = 4;
-	else
-		vdsc_cfg->slice_height = 2;
 
 	/* Gen 11 does not support YCbCr */
 	vdsc_cfg->simple_422 = false;