[PATCH AUTOSEL 6.11 195/244] drm/amd/display: Initialize get_bytes_per_element's default to 1

Sasha Levin
2024-09-25T11:50:20Z

From: Alex Hung <alex.hung@amd.com>

[ Upstream commit 4067f4fa0423a89fb19a30b57231b384d77d2610 ]

Variables, used as denominators and maybe not assigned to other values,
should not be 0. bytes_per_element_y & bytes_per_element_c are
initialized by get_bytes_per_element() which should never return 0.

This fixes 10 DIVIDE_BY_ZERO issues reported by Coverity.

Signed-off-by: Alex Hung <alex.hung@amd.com>
Reviewed-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20v2.c | 2 +-
.../gpu/drm/amd/display/dc/dml/dcn21/display_rq_dlg_calc_21.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20v2.c b/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20v2.c
index 3d95bfa5aca23..ae52510417280 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20v2.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn20/display_rq_dlg_calc_20v2.c
@@ -78,7 +78,7 @@ static void calculate_ttu_cursor(struct display_mode_lib *mode_lib,

static unsigned int get_bytes_per_element(enum source_format_class source_format, bool is_chroma)
{
- unsigned int ret_val = 0;
+ unsigned int ret_val = 1;

if (source_format == dm_444_16) {
if (!is_chroma)
diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn21/display_rq_dlg_calc_21.c b/drivers/gpu/drm/amd/display/dc/dml/dcn21/display_rq_dlg_calc_21.c
index 98502a4f05672..9e1c18b90805d 100644
--- a/drivers/gpu/drm/amd/display/dc/dml/dcn21/display_rq_dlg_calc_21.c
+++ b/drivers/gpu/drm/amd/display/dc/dml/dcn21/display_rq_dlg_calc_21.c
@@ -53,7 +53,7 @@ static void calculate_ttu_cursor(

static unsigned int get_bytes_per_element(enum source_format_class source_format, bool is_chroma)
{
- unsigned int ret_val = 0;
+ unsigned int ret_val = 1;

if (source_format == dm_444_16) {
if (!is_chroma)
--
2.43.0