drm/amd/display: Fix rotated cursor offset calculation

[Why]
Underflow is observed when cursor is still enabled when the cursor
rectangle is outside the bounds of it's surface viewport.

[How]
Update parameters used to determine when cursor should be disabled.

Reviewed-by: Martin Leung <Martin.Leung@amd.com>
Acked-by: Brian Chang <Brian.Chang@amd.com>
Signed-off-by: David Galiffi <David.Galiffi@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 19 insertions, 9 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hubp.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hubp.c
index 52e201e9b091..a142a00bc432 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hubp.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hubp.c
@@ -1179,10 +1179,12 @@ void hubp1_cursor_set_position(
 		const struct dc_cursor_mi_param *param)
 {
 	struct dcn10_hubp *hubp1 = TO_DCN10_HUBP(hubp);
-	int src_x_offset = pos->x - pos->x_hotspot - param->viewport.x;
-	int src_y_offset = pos->y - pos->y_hotspot - param->viewport.y;
+	int x_pos = pos->x - param->viewport.x;
+	int y_pos = pos->y - param->viewport.y;
 	int x_hotspot = pos->x_hotspot;
 	int y_hotspot = pos->y_hotspot;
+	int src_x_offset = x_pos - pos->x_hotspot;
+	int src_y_offset = y_pos - pos->y_hotspot;
 	int cursor_height = (int)hubp->curs_attr.height;
 	int cursor_width = (int)hubp->curs_attr.width;
 	uint32_t dst_x_offset;
@@ -1200,18 +1202,26 @@ void hubp1_cursor_set_position(
 	if (hubp->curs_attr.address.quad_part == 0)
 		return;
 
-	// Rotated cursor width/height and hotspots tweaks for offset calculation
+	// Transform cursor width / height and hotspots for offset calculations
 	if (param->rotation == ROTATION_ANGLE_90 || param->rotation == ROTATION_ANGLE_270) {
 		swap(cursor_height, cursor_width);
+		swap(x_hotspot, y_hotspot);
+
 		if (param->rotation == ROTATION_ANGLE_90) {
-			src_x_offset = pos->x - pos->y_hotspot - param->viewport.x;
-			src_y_offset = pos->y - pos->x_hotspot - param->viewport.y;
+			// hotspot = (-y, x)
+			src_x_offset = x_pos - (cursor_width - x_hotspot);
+			src_y_offset = y_pos - y_hotspot;
+		} else if (param->rotation == ROTATION_ANGLE_270) {
+			// hotspot = (y, -x)
+			src_x_offset = x_pos - x_hotspot;
+			src_y_offset = y_pos - (cursor_height - y_hotspot);
 		}
 	} else if (param->rotation == ROTATION_ANGLE_180) {
+		// hotspot = (-x, -y)
 		if (!param->mirror)
-			src_x_offset = pos->x - param->viewport.x;
+			src_x_offset = x_pos - (cursor_width - x_hotspot);
 
-		src_y_offset = pos->y - param->viewport.y;
+		src_y_offset = y_pos - (cursor_height - y_hotspot);
 	}
 
 	dst_x_offset = (src_x_offset >= 0) ? src_x_offset : 0;
@@ -1248,8 +1258,8 @@ void hubp1_cursor_set_position(
 			CURSOR_Y_POSITION, pos->y);
 
 	REG_SET_2(CURSOR_HOT_SPOT, 0,
-			CURSOR_HOT_SPOT_X, x_hotspot,
-			CURSOR_HOT_SPOT_Y, y_hotspot);
+			CURSOR_HOT_SPOT_X, pos->x_hotspot,
+			CURSOR_HOT_SPOT_Y, pos->y_hotspot);
 
 	REG_SET(CURSOR_DST_OFFSET, 0,
 			CURSOR_DST_X_OFFSET, dst_x_offset);