drm/amd/display: Fix Divide by 0 in memory calculations

From Murton Liu
fc5293ab6c48710eed5df3b40e808e3a3c560e2d in linux 4.19.y/4.19.47
59979bf8be1784ebfc44215031c6c88ca22ae65d in mainline linux

1 files changed, 15 insertions, 5 deletions

diff --git a/sys/dev/pci/drm/amd/display/dc/dcn10/dcn10_dpp_dscl.c b/sys/dev/pci/drm/amd/display/dc/dcn10/dcn10_dpp_dscl.c
index 4a863a5dab4..321af9af95e 100644
--- a/sys/dev/pci/drm/amd/display/dc/dcn10/dcn10_dpp_dscl.c
+++ b/sys/dev/pci/drm/amd/display/dc/dcn10/dcn10_dpp_dscl.c
@@ -406,15 +406,25 @@ void dpp1_dscl_calc_lb_num_partitions(
 		int *num_part_y,
 		int *num_part_c)
 {
+	int lb_memory_size, lb_memory_size_c, lb_memory_size_a, num_partitions_a,
+	lb_bpc, memory_line_size_y, memory_line_size_c, memory_line_size_a;
+
 	int line_size = scl_data->viewport.width < scl_data->recout.width ?
 			scl_data->viewport.width : scl_data->recout.width;
 	int line_size_c = scl_data->viewport_c.width < scl_data->recout.width ?
 			scl_data->viewport_c.width : scl_data->recout.width;
-	int lb_bpc = dpp1_dscl_get_lb_depth_bpc(scl_data->lb_params.depth);
-	int memory_line_size_y = (line_size * lb_bpc + 71) / 72; /* +71 to ceil */
-	int memory_line_size_c = (line_size_c * lb_bpc + 71) / 72; /* +71 to ceil */
-	int memory_line_size_a = (line_size + 5) / 6; /* +5 to ceil */
-	int lb_memory_size, lb_memory_size_c, lb_memory_size_a, num_partitions_a;
+
+	if (line_size == 0)
+		line_size = 1;
+
+	if (line_size_c == 0)
+		line_size_c = 1;
+
+
+	lb_bpc = dpp1_dscl_get_lb_depth_bpc(scl_data->lb_params.depth);
+	memory_line_size_y = (line_size * lb_bpc + 71) / 72; /* +71 to ceil */
+	memory_line_size_c = (line_size_c * lb_bpc + 71) / 72; /* +71 to ceil */
+	memory_line_size_a = (line_size + 5) / 6; /* +5 to ceil */
 
 	if (lb_config == LB_MEMORY_CONFIG_1) {
 		lb_memory_size = 816;