From: Wesley Chalmers wesley.chalmers@amd.com

[WHY] Currently, when insert_plane is called with insert_above_mpcc parameter that is equal to tree->opp_list, the function returns NULL.

[HOW] Instead, the function should insert the plane at the top of the tree.

Cc: Mario Limonciello mario.limonciello@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Reviewed-by: Jun Lei jun.lei@amd.com Acked-by: Tom Chung chiahsuan.chung@amd.com Signed-off-by: Wesley Chalmers wesley.chalmers@amd.com --- drivers/gpu/drm/amd/display/dc/dcn10/dcn10_mpc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 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 8e9384094f6d..f2f55565e98a 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_mpc.c +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_mpc.c @@ -212,8 +212,9 @@ struct mpcc *mpc1_insert_plane( /* check insert_above_mpcc exist in tree->opp_list */ struct mpcc *temp_mpcc = tree->opp_list;

- while (temp_mpcc && temp_mpcc->mpcc_bot != insert_above_mpcc) - temp_mpcc = temp_mpcc->mpcc_bot; + if (temp_mpcc != insert_above_mpcc) + while (temp_mpcc && temp_mpcc->mpcc_bot != insert_above_mpcc) + temp_mpcc = temp_mpcc->mpcc_bot; if (temp_mpcc == NULL) return NULL; }