[PATCH 03/26] drm/amd/display: Fix divide by zero in CURSOR_DST_X_OFFSET calculation

[Fangzhi Zuo]

From: George Shen <george.shen at amd.com>

[Why]
Certain situations cause pipes to have a recout of 0, such as when the
dst_rect lies completely outside of a given ODM slice.

[How]
Skip calculation that transforms cursor coordinates to viewport space.

Reviewed-by: Alvin Lee <alvin.lee2 at amd.com>
Signed-off-by: Jerry Zuo <jerry.zuo at amd.com>
Signed-off-by: George Shen <george.shen at amd.com>
---
 .../drm/amd/display/dc/hubp/dcn401/dcn401_hubp.c  | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/hubp/dcn401/dcn401_hubp.c b/drivers/gpu/drm/amd/display/dc/hubp/dcn401/dcn401_hubp.c
index f0c45a74c2e5..eb0da6c6b87c 100644
--- a/drivers/gpu/drm/amd/display/dc/hubp/dcn401/dcn401_hubp.c
+++ b/drivers/gpu/drm/amd/display/dc/hubp/dcn401/dcn401_hubp.c
@@ -677,12 +677,23 @@ void hubp401_cursor_set_position(
 	int rec_x_offset = x_pos - pos->x_hotspot;
 	int rec_y_offset = y_pos - pos->y_hotspot;
 	int dst_x_offset;
-	int x_pos_viewport = x_pos * param->viewport.width / param->recout.width;
-	int x_hot_viewport = pos->x_hotspot * param->viewport.width / param->recout.width;
+	int x_pos_viewport = 0;
+	int x_hot_viewport = 0;
 	uint32_t cur_en = pos->enable ? 1 : 0;
 
 	hubp->curs_pos = *pos;
 
+	/* Recout is zero for pipes if the entire dst_rect is contained
+	 * within preceeding ODM slices.
+	 */
+	if (param->recout.width) {
+		x_pos_viewport = x_pos * param->viewport.width / param->recout.width;
+		x_hot_viewport = pos->x_hotspot * param->viewport.width / param->recout.width;
+	} else {
+		ASSERT(!cur_en || x_pos == 0);
+		ASSERT(!cur_en || pos->x_hotspot == 0);
+	}
+
 	/*
 	 * Guard aganst cursor_set_position() from being called with invalid
 	 * attributes
-- 
2.34.1