This is a note to let you know that I've just added the patch titled
drm/display/dp_mst: Fix down/up message handling after sink disconnect
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-display-dp_mst-fix-down-up-message-handling-after-sink-disconnect.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 1d082618bbf3b6755b8cc68c0a8122af2842d593 Mon Sep 17 00:00:00 2001
From: Imre Deak <imre.deak@xxxxxxxxx>
Date: Wed, 14 Dec 2022 20:42:56 +0200
Subject: drm/display/dp_mst: Fix down/up message handling after sink disconnect
From: Imre Deak <imre.deak@xxxxxxxxx>
commit 1d082618bbf3b6755b8cc68c0a8122af2842d593 upstream.
If the sink gets disconnected during receiving a multi-packet DP MST AUX
down-reply/up-request sideband message, the state keeping track of which
packets have been received already is not reset. This results in a failed
sanity check for the subsequent message packet received after a sink is
reconnected (due to the pending message not yet completed with an
end-of-message-transfer packet), indicated by the
"sideband msg set header failed"
error.
Fix the above by resetting the up/down message reception state after a
disconnect event.
Cc: Lyude Paul <lyude@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v3.17+
Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20221214184258.2869417-1-imre.deak@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/drm_dp_mst_topology.c | 3 +++
1 file changed, 3 insertions(+)
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -3781,6 +3781,9 @@ int drm_dp_mst_topology_mgr_set_mst(stru
set_bit(0, &mgr->payload_mask);
mgr->vcpi_mask = 0;
mgr->payload_id_table_cleared = false;
+
+ memset(&mgr->down_rep_recv, 0, sizeof(mgr->down_rep_recv));
+ memset(&mgr->up_req_recv, 0, sizeof(mgr->up_req_recv));
}
out_unlock:
Patches currently in stable-queue which might be from imre.deak@xxxxxxxxx are
queue-5.15/drm-display-dp_mst-fix-down-message-handling-after-a-packet-reception-error.patch
queue-5.15/drm-display-dp_mst-fix-down-up-message-handling-after-sink-disconnect.patch
