The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 1241aedb6b5c7a5a8ad73e5eb3a41cfe18a3e00e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '16784480483547@kroah.com' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:

1241aedb6b5c ("drm/display/dp_mst: Fix down message handling after a packet reception error") da68386d9edb ("drm: Rename dp/ to display/") 6c64ae228f08 ("Backmerge tag 'v5.17-rc6' into drm-next")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 1241aedb6b5c7a5a8ad73e5eb3a41cfe18a3e00e Mon Sep 17 00:00:00 2001 From: Imre Deak imre.deak@intel.com Date: Wed, 14 Dec 2022 20:42:57 +0200 Subject: [PATCH] drm/display/dp_mst: Fix down message handling after a packet reception error

After an error during receiving a packet for a multi-packet DP MST sideband message, the state tracking which packets have been received already is not reset. This prevents the reception of subsequent down messages (due to the pending message not yet completed with an end-of-message-transfer packet).

Fix the above by resetting the reception state after a packet error.

Cc: Lyude Paul lyude@redhat.com Cc: stable@vger.kernel.org # v3.17+ Signed-off-by: Imre Deak imre.deak@intel.com Reviewed-by: Lyude Paul lyude@redhat.com Link: https://patchwork.freedesktop.org/patch/msgid/20221214184258.2869417-2-imre....

diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c index 90819fff2c9b..01350510244f 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -3856,7 +3856,7 @@ static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr) struct drm_dp_sideband_msg_rx *msg = &mgr->down_rep_recv;

if (!drm_dp_get_one_sb_msg(mgr, false, &mstb)) - goto out; + goto out_clear_reply;

/* Multi-packet message transmission, don't clear the reply */ if (!msg->have_eomt)