From d6231e4ed43d1c83a2b5450ea31630a81395ba3a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Tue, 31 May 2022 22:18:44 +0300
Subject: drm/i915: Treat DMRRS as static DRRS
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Git-commit: 5a18db2e92a3556ccacc92c031db6e6a7f2b34dc
Patch-mainline: v6.0-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 jsc#PED-2849

Some machines declare DRRS type = seamless, DRRS = no, DMRRS = yes.
I *think* DMRRS stands for "dynamcic media refresh rate", and
I suspect the way it's meant to work is that it lets the driver
switch refresh rates to match the frame rate for media playback.
Obviously for us all that kind of policy stuff is entirely up to
userspace, so the only thing we may do is make the extra refresh
rate(s) available.

So let's treat this case as just static DRRS for now. In the
future We might want to differentiate the "seamless w/ downclocking"
vs. "seamless w/o downclocking" cases so that we could do seamless
refresh rate changes for systems that only claim to support DMRRS.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/125
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220531191844.11313-7-ville.syrjala@linux.intel.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/i915/display/intel_bios.c | 24 +++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index 6c60e6077c85..0922c2eab04b 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -1280,8 +1280,16 @@ parse_panel_driver_features(struct drm_i915_private *i915,
 		 * static DRRS is 0 and DRRS not supported is represented by
 		 * driver->drrs_enabled=false
 		 */
-		if (!driver->drrs_enabled)
-			panel->vbt.drrs_type = DRRS_TYPE_NONE;
+		if (!driver->drrs_enabled && panel->vbt.drrs_type != DRRS_TYPE_NONE) {
+			/*
+			 * FIXME Should DMRRS perhaps be treated as seamless
+			 * but without the automatic downclocking?
+			 */
+			if (driver->dmrrs_enabled)
+				panel->vbt.drrs_type = DRRS_TYPE_STATIC;
+			else
+				panel->vbt.drrs_type = DRRS_TYPE_NONE;
+		}
 
 		panel->vbt.psr.enable = driver->psr_enabled;
 	}
@@ -1311,8 +1319,16 @@ parse_power_conservation_features(struct drm_i915_private *i915,
 	 * static DRRS is 0 and DRRS not supported is represented by
 	 * power->drrs & BIT(panel_type)=false
 	 */
-	if (!(power->drrs & BIT(panel_type)))
-		panel->vbt.drrs_type = DRRS_TYPE_NONE;
+	if (!(power->drrs & BIT(panel_type)) && panel->vbt.drrs_type != DRRS_TYPE_NONE) {
+		/*
+		 * FIXME Should DMRRS perhaps be treated as seamless
+		 * but without the automatic downclocking?
+		 */
+		if (power->dmrrs & BIT(panel_type))
+			panel->vbt.drrs_type = DRRS_TYPE_STATIC;
+		else
+			panel->vbt.drrs_type = DRRS_TYPE_NONE;
+	}
 
 	if (i915->vbt.version >= 232)
 		panel->vbt.edp.hobl = power->hobl & BIT(panel_type);
-- 
2.38.1