From 8de297dc046c180651c0500f8611663ae1c3828a Mon Sep 17 00:00:00 2001 From: Aric Cyr Date: Mon, 11 Jul 2022 10:03:03 -0400 Subject: 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: Josip Pavic Reviewed-by: Jun Lei Acked-by: Alex Hung Signed-off-by: Aric Cyr Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/dcn10/dcn10_mpc.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/gpu/drm/amd/display/dc') 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 11019c2c62cc..769974375b4b 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_mpc.c +++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_mpc.c @@ -49,6 +49,11 @@ void mpc1_set_bg_color(struct mpc *mpc, /* find bottommost mpcc. */ while (bottommost_mpcc->mpcc_bot) { + /* avoid circular linked link */ + ASSERT(bottommost_mpcc != bottommost_mpcc->mpcc_bot); + if (bottommost_mpcc == bottommost_mpcc->mpcc_bot) + break; + bottommost_mpcc = bottommost_mpcc->mpcc_bot; } -- cgit v1.2.3