From: Wayne Lin <Wayne.Lin@amd.com>
To: <dri-devel@lists.freedesktop.org>
Cc: <lyude@redhat.com>, <stable@vger.kernel.org>,
<Nicholas.Kazlauskas@amd.com>, <harry.wentland@amd.com>,
<jerry.zuo@amd.com>, <eryk.brol@amd.com>, <qingqing.zhuo@amd.com>,
Wayne Lin <Wayne.Lin@amd.com>
Subject: [PATCH 1/2] drm/dp_mst: Revise broadcast msg lct & lcr
Date: Mon, 22 Feb 2021 12:00:26 +0800 [thread overview]
Message-ID: <20210222040027.23505-2-Wayne.Lin@amd.com> (raw)
In-Reply-To: <20210222040027.23505-1-Wayne.Lin@amd.com>
[Why & How]
According to DP spec, broadcast message LCT equals to 1 and LCR equals
to 6. Current implementation is incorrect. Fix it.
Signed-off-by: Wayne Lin <Wayne.Lin@amd.com>
Cc: stable@vger.kernel.org
---
drivers/gpu/drm/drm_dp_mst_topology.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 17dbed0a9800..713ef3b42054 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -2727,8 +2727,14 @@ static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
else
hdr->broadcast = 0;
hdr->path_msg = txmsg->path_msg;
- hdr->lct = mstb->lct;
- hdr->lcr = mstb->lct - 1;
+ if (hdr->broadcast) {
+ hdr->lct = 1;
+ hdr->lcr = 6;
+ } else {
+ hdr->lct = mstb->lct;
+ hdr->lcr = mstb->lct - 1;
+ }
+
if (mstb->lct > 1)
memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
--
2.17.1
next prev parent reply other threads:[~2021-02-22 4:03 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-22 4:00 [PATCH 0/2] Set CLEAR_PAYLOAD_ID_TABLE as broadcast request Wayne Lin
2021-02-22 4:00 ` Wayne Lin [this message]
2021-02-22 17:02 ` [PATCH 1/2] drm/dp_mst: Revise broadcast msg lct & lcr Ville Syrjälä
2021-02-22 17:09 ` Ville Syrjälä
2021-02-23 5:32 ` Lin, Wayne
2021-02-23 13:26 ` Ville Syrjälä
2021-02-24 9:47 ` Lin, Wayne
2021-02-22 4:00 ` [PATCH 2/2] drm/dp_mst: Set CLEAR_PAYLOAD_ID_TABLE as broadcast Wayne Lin
2021-02-22 17:00 ` Ville Syrjälä
2021-02-23 5:32 ` Lin, Wayne
2021-02-23 13:21 ` Ville Syrjälä
2021-02-24 18:06 ` [PATCH 0/2] Set CLEAR_PAYLOAD_ID_TABLE as broadcast request Lyude Paul
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