From d099c6bb8782b3812635dfed43615a78df09dae8 Mon Sep 17 00:00:00 2001
From: Vandita Kulkarni <vandita.kulkarni@intel.com>
Date: Tue, 20 Jul 2021 12:19:07 +0530
Subject: drm/i915/display/dsc: Force dsc BPP
Git-commit: dc22aa130565acc4952a13378c782a95cf82b193
Patch-mainline: v5.15-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

Set DSC BPP to the value forced through
debugfs. It can go from bpc to bpp-1.

v2: Use default dsc bpp when we are just
    doing force_dsc_en, use default dsc bpp
    for invalid force_dsc_bpp values. (Jani)

Signed-off-by: Vandita Kulkarni <vandita.kulkarni@intel.com>
Reviewed-by: Swati Sharma <swati2.sharma@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210720064907.9771-4-vandita.kulkarni@intel.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 4d6527c8d407..2526c9c8c690 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -1274,6 +1274,23 @@ static int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
 							       pipe_config->pipe_bpp);
 		pipe_config->dsc.slice_count = dsc_dp_slice_count;
 	}
+
+	/* As of today we support DSC for only RGB */
+	if (intel_dp->force_dsc_bpp) {
+		if (intel_dp->force_dsc_bpp >= 8 &&
+		    intel_dp->force_dsc_bpp < pipe_bpp) {
+			drm_dbg_kms(&dev_priv->drm,
+				    "DSC BPP forced to %d",
+				    intel_dp->force_dsc_bpp);
+			pipe_config->dsc.compressed_bpp =
+						intel_dp->force_dsc_bpp;
+		} else {
+			drm_dbg_kms(&dev_priv->drm,
+				    "Invalid DSC BPP %d",
+				    intel_dp->force_dsc_bpp);
+		}
+	}
+
 	/*
 	 * VDSC engine operates at 1 Pixel per clock, so if peak pixel rate
 	 * is greater than the maximum Cdclock and if slice count is even
-- 
2.38.1