This is a note to let you know that I've just added the patch titled
drm/dp/mst: Read the extended DPCD capabilities during system resume
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-dp-mst-read-the-extended-dpcd-capabilities-durin.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.
commit 8694527edadbe03effe336ee4e9544b1cbf0ec56
Author: Imre Deak <imre.deak@xxxxxxxxx>
Date: Tue Jun 14 12:45:37 2022 +0300
drm/dp/mst: Read the extended DPCD capabilities during system resume
[ Upstream commit 7a710a8bc909313951eb9252d8419924c771d7c2 ]
The WD22TB4 Thunderbolt dock at least will revert its DP_MAX_LINK_RATE
from HBR3 to HBR2 after system suspend/resume if the DP_DP13_DPCD_REV
registers are not read subsequently also as required.
Fix this by reading DP_DP13_DPCD_REV registers as well, matching what is
done during connector detection. While at it also fix up the same call
in drm_dp_mst_dump_topology().
Cc: Lyude Paul <lyude@xxxxxxxxxx>
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5292
Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v5.14+
Reviewed-by: Lyude Paul <lyude@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20220614094537.885472-1-imre.deak@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index b3e3babe18c0..2a586e6489da 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -3860,9 +3860,7 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
if (!mgr->mst_primary)
goto out_fail;
- ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd,
- DP_RECEIVER_CAP_SIZE);
- if (ret != DP_RECEIVER_CAP_SIZE) {
+ if (drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd) < 0) {
drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n");
goto out_fail;
}
@@ -4894,8 +4892,7 @@ void drm_dp_mst_dump_topology(struct seq_file *m,
u8 buf[DP_PAYLOAD_TABLE_SIZE];
int ret;
- ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
- if (ret) {
+ if (drm_dp_read_dpcd_caps(mgr->aux, buf) < 0) {
seq_printf(m, "dpcd read failed\n");
goto out;
}
