This is a note to let you know that I've just added the patch titled
drm/dp_mst: Revise broadcast msg lct & lcr
to the 5.10-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-dp_mst-revise-broadcast-msg-lct-lcr.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 419e91ea3143bf26991442465ac64d9461e98d96 Mon Sep 17 00:00:00 2001
From: Wayne Lin <Wayne.Lin@xxxxxxx>
Date: Wed, 24 Feb 2021 18:15:20 +0800
Subject: drm/dp_mst: Revise broadcast msg lct & lcr
From: Wayne Lin <Wayne.Lin@xxxxxxx>
commit 419e91ea3143bf26991442465ac64d9461e98d96 upstream.
[Why & How]
According to DP spec, broadcast message LCT equals to 1 and LCR equals
to 6. Current implementation is incorrect. Fix it.
In addition, revise a bit the hdr->rad handling to include broadcast
case.
Signed-off-by: Wayne Lin <Wayne.Lin@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx>
Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20210224101521.6713-2-Wayne.Lin@xxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/drm_dp_mst_topology.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -2829,10 +2829,15 @@ static int set_hdr_from_dst_qlock(struct
else
hdr->broadcast = 0;
hdr->path_msg = txmsg->path_msg;
- hdr->lct = mstb->lct;
- hdr->lcr = mstb->lct - 1;
- if (mstb->lct > 1)
- memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
+ if (hdr->broadcast) {
+ hdr->lct = 1;
+ hdr->lcr = 6;
+ } else {
+ hdr->lct = mstb->lct;
+ hdr->lcr = mstb->lct - 1;
+ }
+
+ memcpy(hdr->rad, mstb->rad, hdr->lct / 2);
return 0;
}
Patches currently in stable-queue which might be from Wayne.Lin@xxxxxxx are
queue-5.10/drm-dp_mst-revise-broadcast-msg-lct-lcr.patch
queue-5.10/drm-dp_mst-set-clear_payload_id_table-as-broadcast.patch
