[PATCH 1/2][SRU][J/OEM-5.14/OEM-5.17] drm/dp/mst: Read the extended DPCD capabilities during system resume
Koba Ko
koba.ko at canonical.com
Tue Jun 21 05:34:00 UTC 2022
From: Imre Deak <imre.deak at intel.com>
BugLink: https://bugs.launchpad.net/bugs/1979267
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 at redhat.com>
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5292
Signed-off-by: Imre Deak <imre.deak at intel.com>
Reviewed-by: Jani Nikula <jani.nikula at intel.com>
Reviewed-by: Lyude Paul <lyude at redhat.com>
Ref: https://patchwork.freedesktop.org/patch/489424/?series=105101&rev=1
Signed-off-by: Koba Ko <koba.ko at canonical.com>
---
drivers/gpu/drm/drm_dp_mst_topology.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 86d13d6bc4631..e327c14d66cd3 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;
}
@@ -4893,8 +4891,7 @@ 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;
}
--
2.25.1
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