2 files changed, 45 insertions, 26 deletions

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 d3100f641ac6..f58fa5da7fe5 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -3610,13 +3610,15 @@ static void update_connector_ext_caps(struct amdgpu_dm_connector *aconnector)
 
 	luminance_range = &conn_base->display_info.luminance_range;
 
-	if (luminance_range->max_luminance) {
-		caps->aux_min_input_signal = luminance_range->min_luminance;
+	if (luminance_range->max_luminance)
 		caps->aux_max_input_signal = luminance_range->max_luminance;
-	} else {
-		caps->aux_min_input_signal = 0;
+	else
 		caps->aux_max_input_signal = 512;
-	}
+
+	if (luminance_range->min_luminance)
+		caps->aux_min_input_signal = luminance_range->min_luminance;
+	else
+		caps->aux_min_input_signal = 1;
 
 	min_input_signal_override = drm_get_panel_min_brightness_quirk(aconnector->drm_edid);
 	if (min_input_signal_override >= 0)
@@ -4718,9 +4720,23 @@ static int get_brightness_range(const struct amdgpu_dm_backlight_caps *caps,
 	return 1;
 }
 
+/* Rescale from [min..max] to [0..MAX_BACKLIGHT_LEVEL] */
+static inline u32 scale_input_to_fw(int min, int max, u64 input)
+{
+	return DIV_ROUND_CLOSEST_ULL(input * MAX_BACKLIGHT_LEVEL, max - min);
+}
+
+/* Rescale from [0..MAX_BACKLIGHT_LEVEL] to [min..max] */
+static inline u32 scale_fw_to_input(int min, int max, u64 input)
+{
+	return min + DIV_ROUND_CLOSEST_ULL(input * (max - min), MAX_BACKLIGHT_LEVEL);
+}
+
 static void convert_custom_brightness(const struct amdgpu_dm_backlight_caps *caps,
-				      uint32_t *brightness)
+				      unsigned int min, unsigned int max,
+				      uint32_t *user_brightness)
 {
+	u32 brightness = scale_input_to_fw(min, max, *user_brightness);
 	u8 prev_signal = 0, prev_lum = 0;
 	int i = 0;
 
@@ -4731,7 +4747,7 @@ static void convert_custom_brightness(const struct amdgpu_dm_backlight_caps *cap
 		return;
 
 	/* choose start to run less interpolation steps */
-	if (caps->luminance_data[caps->data_points/2].input_signal > *brightness)
+	if (caps->luminance_data[caps->data_points/2].input_signal > brightness)
 		i = caps->data_points/2;
 	do {
 		u8 signal = caps->luminance_data[i].input_signal;
@@ -4742,17 +4758,18 @@ static void convert_custom_brightness(const struct amdgpu_dm_backlight_caps *cap
 		 * brightness < signal: interpolate between previous and current luminance numerator
 		 * brightness > signal: find next data point
 		 */
-		if (*brightness > signal) {
+		if (brightness > signal) {
 			prev_signal = signal;
 			prev_lum = lum;
 			i++;
 			continue;
 		}
-		if (*brightness < signal)
+		if (brightness < signal)
 			lum = prev_lum + DIV_ROUND_CLOSEST((lum - prev_lum) *
-							   (*brightness - prev_signal),
+							   (brightness - prev_signal),
 							   signal - prev_signal);
-		*brightness = DIV_ROUND_CLOSEST(lum * *brightness, 101);
+		*user_brightness = scale_fw_to_input(min, max,
+						     DIV_ROUND_CLOSEST(lum * brightness, 101));
 		return;
 	} while (i < caps->data_points);
 }
@@ -4765,11 +4782,10 @@ static u32 convert_brightness_from_user(const struct amdgpu_dm_backlight_caps *c
 	if (!get_brightness_range(caps, &min, &max))
 		return brightness;
 
-	convert_custom_brightness(caps, &brightness);
+	convert_custom_brightness(caps, min, max, &brightness);
 
-	// Rescale 0..255 to min..max
-	return min + DIV_ROUND_CLOSEST((max - min) * brightness,
-				       AMDGPU_MAX_BL_LEVEL);
+	// Rescale 0..max to min..max
+	return min + DIV_ROUND_CLOSEST_ULL((u64)(max - min) * brightness, max);
 }
 
 static u32 convert_brightness_to_user(const struct amdgpu_dm_backlight_caps *caps,
@@ -4782,8 +4798,8 @@ static u32 convert_brightness_to_user(const struct amdgpu_dm_backlight_caps *cap
 
 	if (brightness < min)
 		return 0;
-	// Rescale min..max to 0..255
-	return DIV_ROUND_CLOSEST(AMDGPU_MAX_BL_LEVEL * (brightness - min),
+	// Rescale min..max to 0..max
+	return DIV_ROUND_CLOSEST_ULL((u64)max * (brightness - min),
 				 max - min);
 }
 
@@ -4908,7 +4924,7 @@ amdgpu_dm_register_backlight_device(struct amdgpu_dm_connector *aconnector)
 	struct drm_device *drm = aconnector->base.dev;
 	struct amdgpu_display_manager *dm = &drm_to_adev(drm)->dm;
 	struct backlight_properties props = { 0 };
-	struct amdgpu_dm_backlight_caps caps = { 0 };
+	struct amdgpu_dm_backlight_caps *caps;
 	char bl_name[16];
 	int min, max;
 
@@ -4922,22 +4938,21 @@ amdgpu_dm_register_backlight_device(struct amdgpu_dm_connector *aconnector)
 		return;
 	}
 
-	amdgpu_acpi_get_backlight_caps(&caps);
-	if (caps.caps_valid && get_brightness_range(&caps, &min, &max)) {
+	caps = &dm->backlight_caps[aconnector->bl_idx];
+	if (get_brightness_range(caps, &min, &max)) {
 		if (power_supply_is_system_supplied() > 0)
-			props.brightness = (max - min) * DIV_ROUND_CLOSEST(caps.ac_level, 100);
+			props.brightness = (max - min) * DIV_ROUND_CLOSEST(caps->ac_level, 100);
 		else
-			props.brightness = (max - min) * DIV_ROUND_CLOSEST(caps.dc_level, 100);
+			props.brightness = (max - min) * DIV_ROUND_CLOSEST(caps->dc_level, 100);
 		/* min is zero, so max needs to be adjusted */
 		props.max_brightness = max - min;
 		drm_dbg(drm, "Backlight caps: min: %d, max: %d, ac %d, dc %d\n", min, max,
-			caps.ac_level, caps.dc_level);
+			caps->ac_level, caps->dc_level);
 	} else
-		props.brightness = AMDGPU_MAX_BL_LEVEL;
+		props.brightness = props.max_brightness = MAX_BACKLIGHT_LEVEL;
 
-	if (caps.data_points && !(amdgpu_dc_debug_mask & DC_DISABLE_CUSTOM_BRIGHTNESS_CURVE))
+	if (caps->data_points && !(amdgpu_dc_debug_mask & DC_DISABLE_CUSTOM_BRIGHTNESS_CURVE))
 		drm_info(drm, "Using custom brightness curve\n");
-	props.max_brightness = AMDGPU_MAX_BL_LEVEL;
 	props.type = BACKLIGHT_RAW;
 
 	snprintf(bl_name, sizeof(bl_name), "amdgpu_bl%d",
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
index d4395b92fb85..9e3e51a2dc49 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
@@ -1029,6 +1029,10 @@ enum dc_edid_status dm_helpers_read_local_edid(
 			return EDID_NO_RESPONSE;
 
 		edid = drm_edid_raw(drm_edid); // FIXME: Get rid of drm_edid_raw()
+		if (!edid ||
+		    edid->extensions >= sizeof(sink->dc_edid.raw_edid) / EDID_LENGTH)
+			return EDID_BAD_INPUT;
+
 		sink->dc_edid.length = EDID_LENGTH * (edid->extensions + 1);
 		memmove(sink->dc_edid.raw_edid, (uint8_t *)edid, sink->dc_edid.length);