From 30fcc338bc66f930dc7f692205474edb7ca6a607 Mon Sep 17 00:00:00 2001
From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Date: Thu, 11 Jul 2019 10:31:10 -0700
Subject: drm/i915/gen12: MBUS B credit change
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Git-commit: 30fcc338bc66f930dc7f692205474edb7ca6a607
Patch-mainline: v5.4-rc1
References: bsc#1152489

Previously, the recommended B credit for all platforms was 24 / number
of pipes, which would give 6 for newer platforms with 4 pipes. However 6
is not enough and we need 12 on these cases.

We also need a different BW credit for these platforms.

Cc: Arthur J Runyan <arthur.j.runyan@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190711173115.28296-17-lucas.demarchi@intel.com
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 drivers/gpu/drm/i915/display/intel_display.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 0a15c0868a0c..79ae8f4e5213 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -6423,8 +6423,14 @@ static void icl_pipe_mbus_enable(struct intel_crtc *crtc)
 	u32 val;
 
 	val = MBUS_DBOX_A_CREDIT(2);
-	val |= MBUS_DBOX_BW_CREDIT(1);
-	val |= MBUS_DBOX_B_CREDIT(8);
+
+	if (INTEL_GEN(dev_priv) >= 12) {
+		val |= MBUS_DBOX_BW_CREDIT(2);
+		val |= MBUS_DBOX_B_CREDIT(12);
+	} else {
+		val |= MBUS_DBOX_BW_CREDIT(1);
+		val |= MBUS_DBOX_B_CREDIT(8);
+	}
 
 	I915_WRITE(PIPE_MBUS_DBOX_CTL(pipe), val);
 }
-- 
2.28.0