[PATCH AUTOSEL 5.13 094/189] drm/amd/display: Fix crash during MPO + ODM combine mode recalculation

Sasha Levin
2021-07-06T11:20:19Z

From: Aric Cyr <aric.cyr@amd.com>

[ Upstream commit 665f28507a2a3d8d72ed9afa9a2b9b17fd43add1 ]

[Why]
When calculating recout width for an MPO plane on a mode that's using
ODM combine, driver can calculate a negative value, resulting in a
crash.

[How]
For negative widths, use zero such that validation will prune the
configuration correctly and disallow MPO.

Signed-off-by: Aric Cyr <aric.cyr@amd.com>
Reviewed-by: Krunoslav Kovac <Krunoslav.Kovac@amd.com>
Acked-by: Stylon Wang <stylon.wang@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/display/dc/core/dc_resource.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
index 78278a10d899..3b1068a09095 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
@@ -776,6 +776,11 @@ static void calculate_recout(struct pipe_ctx *pipe_ctx)
if (split_idx == split_count) {
/* rightmost pipe is the remainder recout */
data->recout.width -= data->h_active * split_count - data->recout.x;
+
+ /* ODM combine cases with MPO we can get negative widths */
+ if (data->recout.width < 0)
+ data->recout.width = 0;
+
data->recout.x = 0;
} else
data->recout.width = data->h_active - data->recout.x;
--
2.30.2