diff options
| author |   Josip Pavic <Josip.Pavic@amd.com> | 2022-07-21 15:33:00 -0400 |
|---|---|---|
| committer |   Alex Deucher <alexander.deucher@amd.com> | 2022-08-10 15:12:06 -0400 |
| commit | 615fc50207fa27453ba7f5fa1abd60a01a498136 (patch) | |
| tree | 7f2812f4e75e849a2d5143a6b870fbd1ec6962f3 | |
| parent | drm/amd/display: Device flash garbage before get in OS (diff) | |
| download | linux-dev-615fc50207fa27453ba7f5fa1abd60a01a498136.tar.xz linux-dev-615fc50207fa27453ba7f5fa1abd60a01a498136.zip | |
drm/amd/display: Avoid MPC infinite loop
[Why]
In some cases MPC tree bottom pipe ends up point to itself. This causes
iterating from top to bottom to hang the system in an infinite loop.
[How]
When looping to next MPC bottom pipe, check that the pointer is not same
as current to avoid infinite loop.
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Josip Pavic <Josip.Pavic@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/dcn10/dcn10_mpc.c | 6 | ||||
| -rw-r--r-- | drivers/gpu/drm/amd/display/dc/dcn20/dcn20_mpc.c | 6 |
2 files changed, 12 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_mpc.c b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_mpc.c index 769974375b4b..8e9384094f6d 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_mpc.c +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_mpc.c @@ -131,6 +131,12 @@ struct mpcc *mpc1_get_mpcc_for_dpp(struct mpc_tree *tree, int dpp_id) while (tmp_mpcc != NULL) { if (tmp_mpcc->dpp_id == dpp_id) return tmp_mpcc; + + /* avoid circular linked list */ + ASSERT(tmp_mpcc != tmp_mpcc->mpcc_bot); + if (tmp_mpcc == tmp_mpcc->mpcc_bot) + break; + tmp_mpcc = tmp_mpcc->mpcc_bot; } return NULL; diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_mpc.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_mpc.c index 3d307dd58e9a..116f67a0b989 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_mpc.c +++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_mpc.c @@ -531,6 +531,12 @@ static struct mpcc *mpc2_get_mpcc_for_dpp(struct mpc_tree *tree, int dpp_id) while (tmp_mpcc != NULL) { if (tmp_mpcc->dpp_id == 0xf || tmp_mpcc->dpp_id == dpp_id) return tmp_mpcc; + + /* avoid circular linked list */ + ASSERT(tmp_mpcc != tmp_mpcc->mpcc_bot); + if (tmp_mpcc == tmp_mpcc->mpcc_bot) + break; + tmp_mpcc = tmp_mpcc->mpcc_bot; } return NULL; |