diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index e0485d76dc59..1b42c4606002 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -426,6 +426,8 @@ static int amdgpu_dm_init_power_module(struct amdgpu_display_manager *dm)
 		init_data[i].use_custom_backlight_caps = false;
 		init_data[i].custom_backlight_caps_config_no = 0;
 		init_data[i].use_linear_backlight_curve = false;
+		if (amdgpu_dc_debug_mask & DC_DISABLE_CUSTOM_BRIGHTNESS_CURVE)
+			init_data[i].use_linear_backlight_curve = true;
 		init_data[i].def_varibright_enable = 0;
 		init_data[i].varibright_level = 0;
 		/*
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c
index b9e90ea449ca..703d0617df6d 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_backlight.c
@@ -39,6 +39,7 @@
 #include "modules/inc/mod_power.h"
 
 #include <linux/backlight.h>
+#include <linux/minmax.h>
 #include <linux/power_supply.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_utils.h>
@@ -118,6 +119,68 @@ static inline u32 scale_fw_to_input(int min, int max, u64 input)
 	return min + DIV_ROUND_CLOSEST_ULL(input * (max - min), AMDGPU_MAX_BL_LEVEL);
 }
 
+static u32 backlight_signal_to_luminance(const struct amdgpu_dm_backlight_caps *caps,
+					 u32 signal)
+{
+	u32 lower_signal, upper_signal;
+	u32 lower_lum, upper_lum;
+	int i;
+
+	if (!caps->data_points)
+		return DIV_ROUND_CLOSEST(signal * 100, AMDGPU_MAX_BL_LEVEL);
+
+	if (signal < caps->luminance_data[0].input_signal) {
+		lower_signal = 0;
+		lower_lum = 0;
+		upper_signal = caps->luminance_data[0].input_signal;
+		upper_lum = caps->luminance_data[0].luminance;
+	} else if (signal >=
+		   caps->luminance_data[caps->data_points - 1].input_signal) {
+		lower_signal = caps->luminance_data[caps->data_points - 1].input_signal;
+		lower_lum = caps->luminance_data[caps->data_points - 1].luminance;
+		upper_signal = caps->max_input_signal;
+		upper_lum = 100;
+	} else {
+		for (i = 1;
+		     i < caps->data_points &&
+		     signal > caps->luminance_data[i].input_signal;
+		     i++)
+			;
+
+		lower_signal = caps->luminance_data[i - 1].input_signal;
+		upper_signal = caps->luminance_data[i].input_signal;
+		lower_lum = caps->luminance_data[i - 1].luminance;
+		upper_lum = caps->luminance_data[i].luminance;
+	}
+
+	if (upper_signal == lower_signal)
+		return upper_lum;
+
+	return lower_lum + DIV_ROUND_CLOSEST((upper_lum - lower_lum) *
+					     (signal - lower_signal),
+					     upper_signal - lower_signal);
+}
+
+static u32 convert_brightness_to_millipercent(const struct amdgpu_dm_backlight_caps *caps,
+					      u32 user_brightness)
+{
+	unsigned int min, max;
+	u32 signal, luminance;
+
+	if (!get_brightness_range(caps, &min, &max))
+		return DIV_ROUND_CLOSEST_ULL((u64)user_brightness * 100000,
+					     MAX_BACKLIGHT_LEVEL);
+
+	user_brightness = clamp(user_brightness, min, max);
+	if (amdgpu_dc_debug_mask & DC_DISABLE_CUSTOM_BRIGHTNESS_CURVE)
+		return DIV_ROUND_CLOSEST_ULL((u64)user_brightness * 100000, max);
+
+	signal = scale_input_to_fw(max, user_brightness);
+	luminance = backlight_signal_to_luminance(caps, signal);
+
+	return min_t(u32, luminance * 1000, 100000);
+}
+
 STATIC_IFN_KUNIT
 void convert_custom_brightness(const struct amdgpu_dm_backlight_caps *caps,
 			       unsigned int min, unsigned int max,
@@ -260,10 +323,10 @@ void amdgpu_dm_backlight_set_level(struct amdgpu_display_manager *dm,
 	struct amdgpu_dm_backlight_caps *caps;
 	struct dc_link *link;
 	u32 brightness = 0;
+	u32 millipercent = 0;
 	bool rc = false, reallow_idle = false;
 	struct drm_connector *connector;
 	struct dc_stream_state *stream;
-	unsigned int min, max;
 
 	list_for_each_entry(connector, &dm->ddev->mode_config.connector_list, head) {
 		struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
@@ -286,12 +349,21 @@ void amdgpu_dm_backlight_set_level(struct amdgpu_display_manager *dm,
 	/* update scratch register */
 	if (bl_idx == 0)
 		amdgpu_atombios_scratch_regs_set_backlight_level(dm->adev, dm->brightness[bl_idx]);
-	brightness = convert_brightness_from_user(caps, dm->brightness[bl_idx]);
-	link = (struct dc_link *)dm->backlight_link[bl_idx];
 
-	/* Apply brightness quirk */
-	if (caps->brightness_mask)
-		brightness |= caps->brightness_mask;
+	link = (struct dc_link *)dm->backlight_link[bl_idx];
+	stream = dm_find_stream_with_link(dm, link);
+	if (!stream)
+		return;
+
+	if (caps->aux_support) {
+		brightness = convert_brightness_from_user(caps, dm->brightness[bl_idx]);
+		/* Apply brightness quirk */
+		if (caps->brightness_mask)
+			brightness |= caps->brightness_mask;
+	} else {
+		millipercent = convert_brightness_to_millipercent(caps,
+								  user_brightness);
+	}
 
 	if (trace_amdgpu_dm_brightness_enabled()) {
 		trace_amdgpu_dm_brightness(__builtin_return_address(0),
@@ -301,10 +373,6 @@ void amdgpu_dm_backlight_set_level(struct amdgpu_display_manager *dm,
 					   power_supply_is_system_supplied() > 0);
 	}
 
-	stream = dm_find_stream_with_link(dm, link);
-	if (!stream)
-		return;
-
 	mutex_lock(&dm->dc_lock);
 	if (dm->dc->caps.ips_support && dm->dc->ctx->dmub_srv->idle_allowed) {
 		dc_allow_idle_optimizations(dm->dc, false);
@@ -316,10 +384,8 @@ void amdgpu_dm_backlight_set_level(struct amdgpu_display_manager *dm,
 			AUX_BL_DEFAULT_TRANSITION_TIME_MS, false, true);
 	} else {
 		/* power module uses millipercent */
-		get_brightness_range(caps, &min, &max);
-		brightness = DIV_ROUND_CLOSEST(brightness * 100, (max - min)) * 1000;
 		rc = mod_power_set_backlight_percent(dm->power_module, stream,
-						     brightness, 0, false);
+						     millipercent, 0, false);
 	}
 
 	/*