diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 42f882c633ee..47a6ba9fbb14 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -1252,6 +1252,9 @@ bool amdgpu_acpi_is_pcie_performance_request_supported(struct amdgpu_device *ade
 int amdgpu_acpi_pcie_performance_request(struct amdgpu_device *adev,
 						u8 perf_req, bool advertise);
 int amdgpu_acpi_pcie_notify_device_ready(struct amdgpu_device *adev);
+
+void amdgpu_acpi_get_backlight_caps(struct amdgpu_device *adev,
+		struct amdgpu_dm_backlight_caps *caps);
 #else
 static inline int amdgpu_acpi_init(struct amdgpu_device *adev) { return 0; }
 static inline void amdgpu_acpi_fini(struct amdgpu_device *adev) { }
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
index 471266901d1b..47db65926d71 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
@@ -65,6 +65,7 @@ struct amdgpu_atif {
 	struct amdgpu_atif_functions functions;
 	struct amdgpu_atif_notification_cfg notification_cfg;
 	struct amdgpu_encoder *encoder_for_bl;
+	struct amdgpu_dm_backlight_caps backlight_caps;
 };
 
 /* Call the ATIF method
@@ -297,6 +298,65 @@ out:
 	return err;
 }
 
+/**
+ * amdgpu_atif_query_backlight_caps - get min and max backlight input signal
+ *
+ * @handle: acpi handle
+ *
+ * Execute the QUERY_BRIGHTNESS_TRANSFER_CHARACTERISTICS ATIF function
+ * to determine the acceptable range of backlight values
+ *
+ * Backlight_caps.caps_valid will be set to true if the query is successful
+ *
+ * The input signals are in range 0-255
+ *
+ * This function assumes the display with backlight is the first LCD
+ *
+ * Returns 0 on success, error on failure.
+ */
+static int amdgpu_atif_query_backlight_caps(struct amdgpu_atif *atif)
+{
+	union acpi_object *info;
+	struct atif_qbtc_output characteristics;
+	struct atif_qbtc_arguments arguments;
+	struct acpi_buffer params;
+	size_t size;
+	int err = 0;
+
+	arguments.size = sizeof(arguments);
+	arguments.requested_display = ATIF_QBTC_REQUEST_LCD1;
+
+	params.length = sizeof(arguments);
+	params.pointer = (void *)&arguments;
+
+	info = amdgpu_atif_call(atif,
+		ATIF_FUNCTION_QUERY_BRIGHTNESS_TRANSFER_CHARACTERISTICS,
+		&params);
+	if (!info) {
+		err = -EIO;
+		goto out;
+	}
+
+	size = *(u16 *) info->buffer.pointer;
+	if (size < 10) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	memset(&characteristics, 0, sizeof(characteristics));
+	size = min(sizeof(characteristics), size);
+	memcpy(&characteristics, info->buffer.pointer, size);
+
+	atif->backlight_caps.caps_valid = true;
+	atif->backlight_caps.min_input_signal =
+			characteristics.min_input_signal;
+	atif->backlight_caps.max_input_signal =
+			characteristics.max_input_signal;
+out:
+	kfree(info);
+	return err;
+}
+
 /**
  * amdgpu_atif_get_sbios_requests - get requested sbios event
  *
@@ -786,6 +846,17 @@ int amdgpu_acpi_init(struct amdgpu_device *adev)
 		}
 	}
 
+	if (atif->functions.query_backlight_transfer_characteristics) {
+		ret = amdgpu_atif_query_backlight_caps(atif);
+		if (ret) {
+			DRM_DEBUG_DRIVER("Call to QUERY_BACKLIGHT_TRANSFER_CHARACTERISTICS failed: %d\n",
+					ret);
+			atif->backlight_caps.caps_valid = false;
+		}
+	} else {
+		atif->backlight_caps.caps_valid = false;
+	}
+
 out:
 	adev->acpi_nb.notifier_call = amdgpu_acpi_event;
 	register_acpi_notifier(&adev->acpi_nb);
@@ -793,6 +864,18 @@ out:
 	return ret;
 }
 
+void amdgpu_acpi_get_backlight_caps(struct amdgpu_device *adev,
+		struct amdgpu_dm_backlight_caps *caps)
+{
+	if (!adev->atif) {
+		caps->caps_valid = false;
+		return;
+	}
+	caps->caps_valid = adev->atif->backlight_caps.caps_valid;
+	caps->min_input_signal = adev->atif->backlight_caps.min_input_signal;
+	caps->max_input_signal = adev->atif->backlight_caps.max_input_signal;
+}
+
 /**
  * amdgpu_acpi_fini - tear down driver acpi support
  *
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 1ed079a6ca81..a5ba1d6990cc 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1589,27 +1589,60 @@ static int amdgpu_dm_mode_config_init(struct amdgpu_device *adev)
 	return 0;
 }
 
+#define AMDGPU_DM_DEFAULT_MIN_BACKLIGHT 12
+#define AMDGPU_DM_DEFAULT_MAX_BACKLIGHT 255
+
 #if defined(CONFIG_BACKLIGHT_CLASS_DEVICE) ||\
 	defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE)
 
+static void amdgpu_dm_update_backlight_caps(struct amdgpu_display_manager *dm)
+{
+#if defined(CONFIG_ACPI)
+	struct amdgpu_dm_backlight_caps caps;
+
+	if (dm->backlight_caps.caps_valid)
+		return;
+
+	amdgpu_acpi_get_backlight_caps(dm->adev, &caps);
+	if (caps.caps_valid) {
+		dm->backlight_caps.min_input_signal = caps.min_input_signal;
+		dm->backlight_caps.max_input_signal = caps.max_input_signal;
+		dm->backlight_caps.caps_valid = true;
+	} else {
+		dm->backlight_caps.min_input_signal =
+				AMDGPU_DM_DEFAULT_MIN_BACKLIGHT;
+		dm->backlight_caps.max_input_signal =
+				AMDGPU_DM_DEFAULT_MAX_BACKLIGHT;
+	}
+#else
+	dm->backlight_min_input_signal = AMDGPU_DM_DEFAULT_MIN_BACKLIGHT;
+	dm->backlight_max_input_signal = AMDGPU_DM_DEFAULT_MAX_BACKLIGHT;
+#endif
+}
+
 static int amdgpu_dm_backlight_update_status(struct backlight_device *bd)
 {
 	struct amdgpu_display_manager *dm = bl_get_data(bd);
+	struct amdgpu_dm_backlight_caps caps;
+	uint32_t brightness = bd->props.brightness;
 
-	/* backlight_pwm_u16_16 parameter is in unsigned 32 bit, 16 bit integer
-	 * and 16 bit fractional, where 1.0 is max backlight value.
-	 * bd->props.brightness is 8 bit format and needs to be converted by
-	 * scaling via copy lower byte to upper byte of 16 bit value.
-	 */
-	uint32_t brightness = bd->props.brightness * 0x101;
-
+	amdgpu_dm_update_backlight_caps(dm);
+	caps = dm->backlight_caps;
 	/*
-	 * PWM interperts 0 as 100% rather than 0% because of HW
-	 * limitation for level 0.  So limiting minimum brightness level
-	 * to 1.
+	 * The brightness input is in the range 0-255
+	 * It needs to be rescaled to be between the
+	 * requested min and max input signal
+	 *
+	 * It also needs to be scaled up by 0x101 to
+	 * match the DC interface which has a range of
+	 * 0 to 0xffff
 	 */
-	if (bd->props.brightness < 1)
-		brightness = 0x101;
+	brightness =
+		brightness
+		* 0x101
+		* (caps.max_input_signal - caps.min_input_signal)
+		/ AMDGPU_MAX_BL_LEVEL
+		+ caps.min_input_signal * 0x101;
 
 	if (dc_link_set_backlight_level(dm->backlight_link,
 			brightness, 0, 0))
@@ -1639,6 +1672,8 @@ amdgpu_dm_register_backlight_device(struct amdgpu_display_manager *dm)
 	char bl_name[16];
 	struct backlight_properties props = { 0 };
 
+	amdgpu_dm_update_backlight_caps(dm);
+
 	props.max_brightness = AMDGPU_MAX_BL_LEVEL;
 	props.brightness = AMDGPU_MAX_BL_LEVEL;
 	props.type = BACKLIGHT_RAW;
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
index 0512a9810913..19cd4626c3c0 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -83,6 +83,18 @@ struct dm_comressor_info {
 	uint64_t gpu_addr;
 };
 
+/**
+ * struct amdgpu_dm_backlight_caps - Usable range of backlight values from ACPI
+ * @min_input_signal: minimum possible input in range 0-255
+ * @max_input_signal: maximum possible input in range 0-255
+ * @caps_valid: true if these values are from the ACPI interface
+ */
+struct amdgpu_dm_backlight_caps {
+	int min_input_signal;
+	int max_input_signal;
+	bool caps_valid;
+};
+
 /**
  * struct amdgpu_display_manager - Central amdgpu display manager device
  *
@@ -158,6 +170,7 @@ struct amdgpu_display_manager {
 	struct backlight_device *backlight_dev;
 
 	const struct dc_link *backlight_link;
+	struct amdgpu_dm_backlight_caps backlight_caps;
 
 	struct mod_freesync *freesync_module;
 
diff --git a/drivers/gpu/drm/amd/include/amd_acpi.h b/drivers/gpu/drm/amd/include/amd_acpi.h
index 8980edfe5fa9..c72cbfe8f684 100644
--- a/drivers/gpu/drm/amd/include/amd_acpi.h
+++ b/drivers/gpu/drm/amd/include/amd_acpi.h
@@ -52,6 +52,30 @@ struct atif_sbios_requests {
 	u8 backlight_level;	/* panel backlight level (0-255) */
 } __packed;
 
+struct atif_qbtc_arguments {
+	u16 size;		/* structure size in bytes (includes size field) */
+	u8 requested_display;	/* which display is requested */
+} __packed;
+
+#define ATIF_QBTC_MAX_DATA_POINTS 99
+
+struct atif_qbtc_data_point {
+	u8 luminance;		/* luminance in percent */
+	u8 ipnut_signal;	/* input signal in range 0-255 */
+} __packed;
+
+struct atif_qbtc_output {
+	u16 size;		/* structure size in bytes (includes size field) */
+	u16 flags;		/* all zeroes */
+	u8 error_code;		/* error code */
+	u8 ac_level;		/* default brightness on AC power */
+	u8 dc_level;		/* default brightness on DC power */
+	u8 min_input_signal;	/* max input signal in range 0-255 */
+	u8 max_input_signal;	/* min input signal in range 0-255 */
+	u8 number_of_points;	/* number of data points */
+	struct atif_qbtc_data_point data_points[ATIF_QBTC_MAX_DATA_POINTS];
+} __packed;
+
 #define ATIF_NOTIFY_MASK	0x3
 #define ATIF_NOTIFY_NONE	0
 #define ATIF_NOTIFY_81		1