From 39c90798c4226e55449843e9ff0e340e24c89828 Mon Sep 17 00:00:00 2001
From: James Calligeros <jcalligeros99@gmail.com>
Date: Mon, 6 Apr 2026 10:25:39 +1000
Subject: [PATCH 1/8] drm: apple: Define IOMFB parameter for Adaptive Sync

IOMFB exposes a method that allows firmware consumers to change
display behaviour parameters at runtime. One such parameter is
IOMFBParameter_adaptive_sync, which allows DCP to be informed
of the desired minimum refresh rate, media target rate, and
fractional rate.

Add an enum to define the supported parameters, and add
IOMFBPARAM_ADAPTIVE_SYNC to it as a starting point.

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 drivers/gpu/drm/apple/iomfb.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/apple/iomfb.h b/drivers/gpu/drm/apple/iomfb.h
index 5799586106713e..8a871db0b94a70 100644
--- a/drivers/gpu/drm/apple/iomfb.h
+++ b/drivers/gpu/drm/apple/iomfb.h
@@ -46,6 +46,15 @@ enum dcpep_type {
 	IOMFB_MESSAGE_TYPE_MSG = 2,
 };
 
+/*
+ * IOMFB supports the setting of a number of parameters
+ * that alter various aspects of the connected sink's
+ * behaviour at runtime.
+ */
+enum iomfb_parameter {
+	IOMFBPARAM_ADAPTIVE_SYNC = 14,
+};
+
 #define IOMFB_MESSAGE_TYPE	GENMASK_ULL( 3,  0)
 
 /* Message */

From adf1383c2076a32ac45ed26222acec86aea977ea Mon Sep 17 00:00:00 2001
From: James Calligeros <jcalligeros99@gmail.com>
Date: Mon, 6 Apr 2026 10:21:44 +1000
Subject: [PATCH 2/8] drm: apple: Do not set IOMFBParameter_adaptive_sync on
 poweron

This was actually unnecessary, and having dcp_on_set_parameter as
a dcp_callback_t will introduce some complicated duplication when
enabling VRR. Remove this callback and just set the display handle
on poweron instead.

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 drivers/gpu/drm/apple/iomfb_template.c | 30 ++++++--------------------
 1 file changed, 6 insertions(+), 24 deletions(-)

diff --git a/drivers/gpu/drm/apple/iomfb_template.c b/drivers/gpu/drm/apple/iomfb_template.c
index 1b7ecbcba925d1..6aaa3888c83198 100644
--- a/drivers/gpu/drm/apple/iomfb_template.c
+++ b/drivers/gpu/drm/apple/iomfb_template.c
@@ -784,26 +784,11 @@ static void dcp_on_set_power_state(struct apple_dcp *dcp, void *out, void *cooki
 	dcp_set_power_state(dcp, false, &req, dcp_on_final, cookie);
 }
 
-static void dcp_on_set_parameter(struct apple_dcp *dcp, void *out, void *cookie)
-{
-	struct dcp_set_parameter_dcp param = {
-		.param = 14,
-		.value = { 0 },
-#if DCP_FW_VER >= DCP_FW_VERSION(13, 2, 0)
-		.count = 3,
-#else
-		.count = 1,
-#endif
-	};
-
-	dcp_set_parameter_dcp(dcp, false, &param, dcp_on_set_power_state, cookie);
-}
-
 void DCP_FW_NAME(iomfb_poweron)(struct apple_dcp *dcp)
 {
 	struct dcp_wait_cookie *cookie;
 	int ret;
-	u32 handle;
+	u32 handle = 0;
 	dev_info(dcp->dev, "dcp_poweron() starting\n");
 
 	cookie = kzalloc(sizeof(*cookie), GFP_KERNEL);
@@ -815,15 +800,12 @@ void DCP_FW_NAME(iomfb_poweron)(struct apple_dcp *dcp)
 	/* increase refcount to ensure the receiver has a reference */
 	kref_get(&cookie->refcount);
 
-	if (dcp->main_display) {
-		handle = 0;
-		dcp_set_display_device(dcp, false, &handle, dcp_on_set_power_state,
-				       cookie);
-	} else {
+	if (!dcp->main_display)
 		handle = 2;
-		dcp_set_display_device(dcp, false, &handle,
-				       dcp_on_set_parameter, cookie);
-	}
+
+	dcp_set_display_device(dcp, false, &handle, dcp_on_set_power_state,
+			       cookie);
+
 	ret = wait_for_completion_timeout(&cookie->done, msecs_to_jiffies(10000));
 
 	if (ret == 0) {

From 7c7b7087475d164eca3e63d48f6d9b86bf2c14ef Mon Sep 17 00:00:00 2001
From: James Calligeros <jcalligeros99@gmail.com>
Date: Fri, 3 Apr 2026 20:31:17 +1000
Subject: [PATCH 3/8] drm: apple: Add preliminary VRR support

DCP supports VRR/Adaptive Sync, with its enormous firmware blob
handling the low-level details for us. Display refresh rate is
determined by the swap timing values provided to DCP on each
swap request.

VRR is activated by setting IOMFBadaptive_sync_parameter::minRR
and then requesting a modeset.

Wire up all of the required KMS properties to expose VRR to
userspace, and tell DCP to enable it when supported. This
enables VRR *unconditionally* for supported sinks, which will
be fixed in a future commit.

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 drivers/gpu/drm/apple/apple_drv.c      |  4 +++
 drivers/gpu/drm/apple/iomfb.c          |  1 +
 drivers/gpu/drm/apple/iomfb_template.c | 46 ++++++++++++++++++++++++--
 drivers/gpu/drm/apple/parser.c         | 12 +++++--
 drivers/gpu/drm/apple/parser.h         |  2 ++
 5 files changed, 59 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/apple/apple_drv.c b/drivers/gpu/drm/apple/apple_drv.c
index 0f36dad6f96351..31b86e909014ad 100644
--- a/drivers/gpu/drm/apple/apple_drv.c
+++ b/drivers/gpu/drm/apple/apple_drv.c
@@ -335,6 +335,10 @@ static int apple_probe_per_dcp(struct device *dev,
 	if (ret)
 		return ret;
 
+	ret = drm_connector_attach_vrr_capable_property(&connector->base);
+	if (ret)
+		return ret;
+
 	connector->base.polled = DRM_CONNECTOR_POLL_HPD;
 	connector->connected = false;
 	connector->dcp = dcp;
diff --git a/drivers/gpu/drm/apple/iomfb.c b/drivers/gpu/drm/apple/iomfb.c
index 1d9448f0f4dc47..1d90e4a2597303 100644
--- a/drivers/gpu/drm/apple/iomfb.c
+++ b/drivers/gpu/drm/apple/iomfb.c
@@ -244,6 +244,7 @@ void dcp_hotplug(struct work_struct *work)
 
 	if (!connector->connected) {
 		drm_edid_free(connector->drm_edid);
+		drm_connector_set_vrr_capable_property(&connector->base, false);
 		connector->drm_edid = NULL;
 	}
 
diff --git a/drivers/gpu/drm/apple/iomfb_template.c b/drivers/gpu/drm/apple/iomfb_template.c
index 6aaa3888c83198..323cbf1b8b483d 100644
--- a/drivers/gpu/drm/apple/iomfb_template.c
+++ b/drivers/gpu/drm/apple/iomfb_template.c
@@ -546,8 +546,9 @@ static u8 dcpep_cb_prop_chunk(struct apple_dcp *dcp,
 static bool dcpep_process_chunks(struct apple_dcp *dcp,
 				 struct dcp_set_dcpav_prop_end_req *req)
 {
+	struct apple_connector *connector = dcp->connector;
 	struct dcp_parse_ctx ctx;
-	int ret;
+	int ret, i;
 
 	if (!dcp->chunks.data) {
 		dev_warn(dcp->dev, "ignoring spurious end\n");
@@ -589,6 +590,15 @@ static bool dcpep_process_chunks(struct apple_dcp *dcp,
 		dcp_set_dimensions(dcp);
 	}
 
+	if (connector) {
+		for (i = 0; i < dcp->nr_modes; i++) {
+			if (dcp->modes[i].vrr) {
+				drm_connector_set_vrr_capable_property(&connector->base, true);
+				break;
+			}
+		}
+	}
+
 	return true;
 }
 
@@ -1172,6 +1182,33 @@ static void complete_set_digital_out_mode(struct apple_dcp *dcp, void *data,
 	}
 }
 
+/* Changes to Adaptive Sync require a trip through set_digital_out_mode */
+static void dcp_on_set_adaptive_sync(struct apple_dcp *dcp, void *out, void *cookie)
+{
+	dcp_set_digital_out_mode(dcp, false, &dcp->mode,
+				 complete_set_digital_out_mode, cookie);
+}
+
+static void dcp_set_adaptive_sync(struct apple_dcp *dcp, u64 rate, void *cookie)
+{
+	struct dcp_set_parameter_dcp param = {
+		.param = IOMFBPARAM_ADAPTIVE_SYNC,
+		.value = {
+			rate & 0xffffffff, /* minRR */
+			0,                 /* mediaTargetRate */
+			0,                 /* Fractional Rate (?) */
+			0,                 /* unused */
+		},
+#if DCP_FW_VER >= DCP_FW_VERSION(13, 2, 0)
+		.count = 3,
+#else
+		.count = 1,
+#endif
+	};
+
+	dcp_set_parameter_dcp(dcp, false, &param, dcp_on_set_adaptive_sync, cookie);
+}
+
 int DCP_FW_NAME(iomfb_modeset)(struct apple_dcp *dcp,
 			       struct drm_crtc_state *crtc_state)
 {
@@ -1226,8 +1263,11 @@ int DCP_FW_NAME(iomfb_modeset)(struct apple_dcp *dcp,
 
 	dcp->during_modeset = true;
 
-	dcp_set_digital_out_mode(dcp, false, &dcp->mode,
-				 complete_set_digital_out_mode, cookie);
+	if (mode->vrr)
+		dcp_set_adaptive_sync(dcp, mode->min_vrr, cookie);
+	else
+		dcp_set_digital_out_mode(dcp, false, &dcp->mode,
+					 complete_set_digital_out_mode, cookie);
 
 	/*
 	 * The DCP firmware has an internal timeout of ~8 seconds for
diff --git a/drivers/gpu/drm/apple/parser.c b/drivers/gpu/drm/apple/parser.c
index 7c7af18a7c7e15..010cb10d5c1e28 100644
--- a/drivers/gpu/drm/apple/parser.c
+++ b/drivers/gpu/drm/apple/parser.c
@@ -454,6 +454,10 @@ static int parse_mode(struct dcp_parse_ctx *handle,
 			ret = parse_dimension(it.handle, &horiz);
 		else if (!strcmp(key, "VerticalAttributes"))
 			ret = parse_dimension(it.handle, &vert);
+		else if (!strcmp(key, "MinimumVariableRefreshRate"))
+			ret = parse_int(it.handle, &out->min_vrr);
+		else if (!strcmp(key, "MaximumVariableRefreshRate"))
+			ret = parse_int(it.handle, &out->max_vrr);
 		else if (!strcmp(key, "ColorModes"))
 			ret = parse_color_modes(it.handle, out);
 		else if (!strcmp(key, "ID"))
@@ -502,15 +506,17 @@ static int parse_mode(struct dcp_parse_ctx *handle,
 	/*
 	* HACK:
 	* Mark the 120 Hz mode on j314/j316 (identified by resolution) as vrr.
-	* We still do not know how to drive VRR but at least seetinng timestamps
-	* in the the swap_surface message to non-zero values drives the display
-	* at 120 fps.
+	* Setting timestamps in the the swap_surface message to non-zero
+	* values drives the display at 120 fps.
 	*/
 	if (vert.precise_sync_rate >> 16 == 120 &&
 	    ((horiz.active == 3024 && vert.active == 1964) ||
 	     (horiz.active == 3456 && vert.active == 2234)))
 		out->vrr = true;
 
+	if (out->min_vrr && out->max_vrr)
+		out->vrr = true;
+
 	vert.active -= notch_height;
 	vert.sync_width += notch_height;
 
diff --git a/drivers/gpu/drm/apple/parser.h b/drivers/gpu/drm/apple/parser.h
index e03ee06ae98a75..18b85a06e8f9d7 100644
--- a/drivers/gpu/drm/apple/parser.h
+++ b/drivers/gpu/drm/apple/parser.h
@@ -92,6 +92,8 @@ struct dcp_display_mode {
 	struct dcp_color_mode sdr;
 	struct dcp_color_mode best;
 	bool vrr;
+	s64 min_vrr;
+	s64 max_vrr;
 };
 
 struct dimension {

From f7f7e78c84a4429f17a842719b753d1db734cf5c Mon Sep 17 00:00:00 2001
From: James Calligeros <jcalligeros99@gmail.com>
Date: Sat, 4 Apr 2026 17:43:49 +1000
Subject: [PATCH 4/8] drm: apple: Force modeset when VRR is toggled

DCP requires a "modeset" to trigger the upload of the SDP
to the display. On some monitors, this is instant. On others,
this seems to take as long as a real modeset. Given that in
either case we still blank the display, let's just force a
full modeset when VRR is toggled on or off.

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 drivers/gpu/drm/apple/dcp-internal.h   | 1 +
 drivers/gpu/drm/apple/dcp.c            | 5 +++++
 drivers/gpu/drm/apple/iomfb_template.c | 2 +-
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/apple/dcp-internal.h b/drivers/gpu/drm/apple/dcp-internal.h
index f2eb2483c9a880..0a6859448e19eb 100644
--- a/drivers/gpu/drm/apple/dcp-internal.h
+++ b/drivers/gpu/drm/apple/dcp-internal.h
@@ -186,6 +186,7 @@ struct apple_dcp {
 	bool during_modeset;
 	bool valid_mode;
 	bool use_timestamps;
+	bool vrr_enabled;
 	struct dcp_set_digital_out_mode_req mode;
 
 	/* completion for active turning true */
diff --git a/drivers/gpu/drm/apple/dcp.c b/drivers/gpu/drm/apple/dcp.c
index 9dfc3fd002f530..c309b8aa5e61ea 100644
--- a/drivers/gpu/drm/apple/dcp.c
+++ b/drivers/gpu/drm/apple/dcp.c
@@ -361,6 +361,11 @@ int dcp_crtc_atomic_check(struct drm_crtc *crtc, struct drm_atomic_state *state)
 		return -EINVAL;
 	}
 
+	if (dcp->vrr_enabled != crtc_state->vrr_enabled) {
+		dcp->vrr_enabled = crtc_state->vrr_enabled;
+		crtc_state->mode_changed = true;
+	}
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/apple/iomfb_template.c b/drivers/gpu/drm/apple/iomfb_template.c
index 323cbf1b8b483d..ad6af433555115 100644
--- a/drivers/gpu/drm/apple/iomfb_template.c
+++ b/drivers/gpu/drm/apple/iomfb_template.c
@@ -1264,7 +1264,7 @@ int DCP_FW_NAME(iomfb_modeset)(struct apple_dcp *dcp,
 	dcp->during_modeset = true;
 
 	if (mode->vrr)
-		dcp_set_adaptive_sync(dcp, mode->min_vrr, cookie);
+		dcp_set_adaptive_sync(dcp, dcp->vrr_enabled ? mode->min_vrr : 0, cookie);
 	else
 		dcp_set_digital_out_mode(dcp, false, &dcp->mode,
 					 complete_set_digital_out_mode, cookie);

From 126db21a2ef63cc869ebe91ff28979da3482f925 Mon Sep 17 00:00:00 2001
From: James Calligeros <jcalligeros99@gmail.com>
Date: Fri, 3 Apr 2026 21:59:47 +1000
Subject: [PATCH 5/8] drm: apple: Set swap timestamps to sane values for
 Adaptive Sync

Setting these timestamps to a dummy value worked fine for enabling
a fixed 120 Hz mode on the MacBook Pros, however doing so causes
Adaptive Sync displays to simply switch between full and minimum
refresh rates. Setting these timestamps based on the swap pacing
seems to fix this, and makes the display's refresh rate match
the incoming swap rate.

Note that the names and values are best-guess only. These seem
to work fine for driving VRR displays, but may still be incorrect.

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 drivers/gpu/drm/apple/iomfb_template.c | 20 +++++++++++++++-----
 drivers/gpu/drm/apple/iomfb_template.h |  6 +++---
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/apple/iomfb_template.c b/drivers/gpu/drm/apple/iomfb_template.c
index ad6af433555115..12418b5552abc1 100644
--- a/drivers/gpu/drm/apple/iomfb_template.c
+++ b/drivers/gpu/drm/apple/iomfb_template.c
@@ -1299,6 +1299,15 @@ int DCP_FW_NAME(iomfb_modeset)(struct apple_dcp *dcp,
 	return 0;
 }
 
+/*
+ * DCP timestamps are expressed in system timer ticks. Approximate
+ * this by converting from ktime nanoseconds to 24 MHz ticks.
+ */
+static u64 ns_to_mach(u64 ns)
+{
+	return ns * 3 / 125;
+}
+
 void DCP_FW_NAME(iomfb_flush)(struct apple_dcp *dcp, struct drm_crtc *crtc, struct drm_atomic_state *state)
 {
 	struct drm_plane *plane;
@@ -1415,12 +1424,13 @@ void DCP_FW_NAME(iomfb_flush)(struct apple_dcp *dcp, struct drm_crtc *crtc, stru
 
 	if (has_surface && dcp->use_timestamps) {
 		/*
-		 * Fake timstamps to get 120hz refresh rate. It looks
-		 * like the actual value does not matter, as long  as it is non zero.
+		 * TODO: ascertain with certainty what these timestamps
+		 * are. These names are guesses based on what macOS populates
+		 * them with. These values seem to work well with VRR.
 		 */
-		req->swap.ts1 = 120;
-		req->swap.ts2 = 120;
-		req->swap.ts3 = 120;
+		req->swap.presentation_time = ns_to_mach(ktime_get_ns());
+		req->swap.last_pres_time = ns_to_mach(ktime_to_ns(dcp->swap_start));
+		req->swap.submit_time = req->swap.presentation_time;
 	}
 
 	/* These fields should be set together */
diff --git a/drivers/gpu/drm/apple/iomfb_template.h b/drivers/gpu/drm/apple/iomfb_template.h
index 8efab49cc53d08..1fea73ff0b95c7 100644
--- a/drivers/gpu/drm/apple/iomfb_template.h
+++ b/drivers/gpu/drm/apple/iomfb_template.h
@@ -18,14 +18,14 @@
 #include "version_utils.h"
 
 struct DCP_FW_NAME(dcp_swap) {
-	u64 ts1;
-	u64 ts2;
+	u64 presentation_time;
+	u64 last_pres_time;
 
 	u64 unk_10;
 	u64 unk_18;
 	u64 ts64_unk;
 	u64 unk_28;
-	u64 ts3;
+	u64 submit_time;
 	u64 unk_38;
 
 	u64 flags1;

From bdb680f156a07be1def4a34edb17dbd002943149 Mon Sep 17 00:00:00 2001
From: James Calligeros <jcalligeros99@gmail.com>
Date: Sat, 4 Apr 2026 23:32:06 +1000
Subject: [PATCH 6/8] drm: apple: Set min and max VRRs for MacBook Pros

Since these machines do not have proper EDID/DisplayID data, we need
to help the driver along a little bit. We know that "ProMotion" displays
can do 24-120 Hz VRR, so let's populate the mode with those values.

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 drivers/gpu/drm/apple/parser.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/apple/parser.c b/drivers/gpu/drm/apple/parser.c
index 010cb10d5c1e28..40f318c8dfd86e 100644
--- a/drivers/gpu/drm/apple/parser.c
+++ b/drivers/gpu/drm/apple/parser.c
@@ -511,8 +511,11 @@ static int parse_mode(struct dcp_parse_ctx *handle,
 	*/
 	if (vert.precise_sync_rate >> 16 == 120 &&
 	    ((horiz.active == 3024 && vert.active == 1964) ||
-	     (horiz.active == 3456 && vert.active == 2234)))
+	     (horiz.active == 3456 && vert.active == 2234))) {
+		out->min_vrr = 24 << 16;
+		out->max_vrr = 120 << 16;
 		out->vrr = true;
+	}
 
 	if (out->min_vrr && out->max_vrr)
 		out->vrr = true;

From 157e8a1d07e3e3493fe75f2c1ce87ea64145f09f Mon Sep 17 00:00:00 2001
From: James Calligeros <jcalligeros99@gmail.com>
Date: Sun, 5 Apr 2026 13:08:29 +1000
Subject: [PATCH 7/8] drm: apple: Only use swap timestamps if VRR is actually
 active

macOS is inconsistent with how it uses DCP timestamps. Some swaps
don't use them at all. We know they are required for VRR display
modes to work properly, so let's just turn them on when we are
connected to a VRR display. This includes the 120 Hz mode on
the 14" and 16" MacBook Pros.

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 drivers/gpu/drm/apple/iomfb_template.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/apple/iomfb_template.c b/drivers/gpu/drm/apple/iomfb_template.c
index 12418b5552abc1..dcb740127b2536 100644
--- a/drivers/gpu/drm/apple/iomfb_template.c
+++ b/drivers/gpu/drm/apple/iomfb_template.c
@@ -1248,8 +1248,8 @@ int DCP_FW_NAME(iomfb_modeset)(struct apple_dcp *dcp,
 		.timing_mode_id = mode->timing_mode_id
 	};
 
-	/* Keep track of suspected vrr modes */
-	dcp->use_timestamps = mode->vrr;
+	/* Use DCP swap timestamps on MacBook Pros with VRR */
+	dcp->use_timestamps = mode->vrr && dcp->main_display;
 
 	cookie = kzalloc(sizeof(*cookie), GFP_KERNEL);
 	if (!cookie) {
@@ -1422,7 +1422,7 @@ void DCP_FW_NAME(iomfb_flush)(struct apple_dcp *dcp, struct drm_crtc *crtc, stru
 		req->clear = 1;
 	}
 
-	if (has_surface && dcp->use_timestamps) {
+	if (has_surface && (dcp->use_timestamps || crtc_state->vrr_enabled)) {
 		/*
 		 * TODO: ascertain with certainty what these timestamps
 		 * are. These names are guesses based on what macOS populates

From 31bf70daae3525a4d1d4bbfd7fe07355c0281e3f Mon Sep 17 00:00:00 2001
From: James Calligeros <jcalligeros99@gmail.com>
Date: Tue, 7 Apr 2026 21:43:32 +1000
Subject: [PATCH 8/8] NOUPSTREAM: drm: apple: Hide VRR behind a module
 parameter

Given that DCP requires a modeset to activate VRR, and given that
this is explicitly banned by KMS API contract and VESA DisplayPort
specification, hide this experimental support behind a module param.

Interestingly, the HDMI spec does not require a modeset-free VRR
transition. For this reason, it is expected that the KMS API contract
may change in the future, as both Intel and AMD hardware require
a modeset to enable VRR in some circumstances. Either VRR will be
expected to be enabled whenever it is supported, *or* modesetting
to toggle it on or off will be allowed. When that happens, this
commit *must* be reverted.

Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
---
 drivers/gpu/drm/apple/dcp.c            |  4 ++++
 drivers/gpu/drm/apple/iomfb_template.c | 28 ++++++++++++++------------
 2 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/apple/dcp.c b/drivers/gpu/drm/apple/dcp.c
index c309b8aa5e61ea..d830ff72ce8388 100644
--- a/drivers/gpu/drm/apple/dcp.c
+++ b/drivers/gpu/drm/apple/dcp.c
@@ -58,6 +58,10 @@ static bool unstable_edid = true;
 module_param(unstable_edid, bool, 0644);
 MODULE_PARM_DESC(unstable_edid, "Enable unstable EDID retrival support");
 
+bool vrr;
+module_param(vrr, bool, 0644);
+MODULE_PARM_DESC(vrr, "Enable Adaptive Sync/ProMotion on supported displays");
+
 /* copied and simplified from drm_vblank.c */
 static void send_vblank_event(struct drm_device *dev,
 		struct drm_pending_vblank_event *e,
diff --git a/drivers/gpu/drm/apple/iomfb_template.c b/drivers/gpu/drm/apple/iomfb_template.c
index dcb740127b2536..351ceb605f9749 100644
--- a/drivers/gpu/drm/apple/iomfb_template.c
+++ b/drivers/gpu/drm/apple/iomfb_template.c
@@ -34,6 +34,8 @@
 /* Register defines used in bandwidth setup structure */
 #define REG_DOORBELL_BIT(idx) (2 + (idx))
 
+extern bool vrr;
+
 struct dcp_wait_cookie {
 	struct kref refcount;
 	struct completion done;
@@ -546,9 +548,9 @@ static u8 dcpep_cb_prop_chunk(struct apple_dcp *dcp,
 static bool dcpep_process_chunks(struct apple_dcp *dcp,
 				 struct dcp_set_dcpav_prop_end_req *req)
 {
-	struct apple_connector *connector = dcp->connector;
+	// struct apple_connector *connector = dcp->connector;
 	struct dcp_parse_ctx ctx;
-	int ret, i;
+	int ret; //, i;
 
 	if (!dcp->chunks.data) {
 		dev_warn(dcp->dev, "ignoring spurious end\n");
@@ -590,14 +592,14 @@ static bool dcpep_process_chunks(struct apple_dcp *dcp,
 		dcp_set_dimensions(dcp);
 	}
 
-	if (connector) {
-		for (i = 0; i < dcp->nr_modes; i++) {
-			if (dcp->modes[i].vrr) {
-				drm_connector_set_vrr_capable_property(&connector->base, true);
-				break;
-			}
-		}
-	}
+	// if (connector) {
+	// 	for (i = 0; i < dcp->nr_modes; i++) {
+	// 		if (dcp->modes[i].vrr) {
+	// 			drm_connector_set_vrr_capable_property(&connector->base, true);
+	// 			break;
+	// 		}
+	// 	}
+	// }
 
 	return true;
 }
@@ -1263,8 +1265,8 @@ int DCP_FW_NAME(iomfb_modeset)(struct apple_dcp *dcp,
 
 	dcp->during_modeset = true;
 
-	if (mode->vrr)
-		dcp_set_adaptive_sync(dcp, dcp->vrr_enabled ? mode->min_vrr : 0, cookie);
+	if (mode->vrr && vrr)
+		dcp_set_adaptive_sync(dcp, mode->min_vrr, cookie);
 	else
 		dcp_set_digital_out_mode(dcp, false, &dcp->mode,
 					 complete_set_digital_out_mode, cookie);
@@ -1422,7 +1424,7 @@ void DCP_FW_NAME(iomfb_flush)(struct apple_dcp *dcp, struct drm_crtc *crtc, stru
 		req->clear = 1;
 	}
 
-	if (has_surface && (dcp->use_timestamps || crtc_state->vrr_enabled)) {
+	if (has_surface && (dcp->use_timestamps || crtc_state->vrr_enabled || vrr)) {
 		/*
 		 * TODO: ascertain with certainty what these timestamps
 		 * are. These names are guesses based on what macOS populates