public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
* [PATCH AUTOSEL 5.10 01/11] drm/amd/display: Avoid MPC infinite loop
@ 2022-08-25  1:38 Sasha Levin
  2022-08-25  1:38 ` [PATCH AUTOSEL 5.10 02/11] drm/amd/display: For stereo keep "FLIP_ANY_FRAME" Sasha Levin
                   ` (9 more replies)
  0 siblings, 10 replies; 11+ messages in thread
From: Sasha Levin @ 2022-08-25  1:38 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Josip Pavic, Jun Lei, Alex Hung, Aric Cyr, Daniel Wheeler,
	Alex Deucher, Sasha Levin, harry.wentland, sunpeng.li,
	Rodrigo.Siqueira, christian.koenig, Xinhui.Pan, airlied, daniel,
	chiahsuan.chung, jiapeng.chong, isabbasso, amd-gfx, dri-devel

From: Josip Pavic <Josip.Pavic@amd.com>

[ Upstream commit 8de297dc046c180651c0500f8611663ae1c3828a ]

[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 <Josip.Pavic@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Aric Cyr <aric.cyr@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/dcn10/dcn10_mpc.c | 6 ++++++
 drivers/gpu/drm/amd/display/dc/dcn20/dcn20_mpc.c | 6 ++++++
 2 files changed, 12 insertions(+)

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 3fcd408e9103..855682590c1b 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_mpc.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn10/dcn10_mpc.c
@@ -125,6 +125,12 @@ 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 99cc095dc33c..a701ea56c0aa 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_mpc.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_mpc.c
@@ -533,6 +533,12 @@ 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;
-- 
2.35.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2022-08-25  1:44 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2022-08-25  1:38 [PATCH AUTOSEL 5.10 01/11] drm/amd/display: Avoid MPC infinite loop Sasha Levin
2022-08-25  1:38 ` [PATCH AUTOSEL 5.10 02/11] drm/amd/display: For stereo keep "FLIP_ANY_FRAME" Sasha Levin
2022-08-25  1:38 ` [PATCH AUTOSEL 5.10 03/11] drm/amd/display: clear optc underflow before turn off odm clock Sasha Levin
2022-08-25  1:38 ` [PATCH AUTOSEL 5.10 04/11] neigh: fix possible DoS due to net iface start/stop loop Sasha Levin
2022-08-25  1:38 ` [PATCH AUTOSEL 5.10 05/11] s390/hypfs: avoid error message under KVM Sasha Levin
2022-08-25  1:38 ` [PATCH AUTOSEL 5.10 06/11] drm/amd/pm: add missing ->fini_microcode interface for Sienna Cichlid Sasha Levin
2022-08-25  1:38 ` [PATCH AUTOSEL 5.10 07/11] drm/amd/display: Fix pixel clock programming Sasha Levin
2022-08-25  1:38 ` [PATCH AUTOSEL 5.10 08/11] drm/amdgpu: Increase tlb flush timeout for sriov Sasha Levin
2022-08-25  1:38 ` [PATCH AUTOSEL 5.10 09/11] netfilter: conntrack: NF_CONNTRACK_PROCFS should no longer default to y Sasha Levin
2022-08-25  1:38 ` [PATCH AUTOSEL 5.10 10/11] btrfs: tree-checker: check for overlapping extent items Sasha Levin
2022-08-25  1:38 ` [PATCH AUTOSEL 5.10 11/11] ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead Sasha Levin

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox