Occasionally there are LINK_ADDRESS sideband messages timing out with the
Lenovo MST dock + Dell MST monitor(w/ in-built branch) setup I have. These
failures lead to the display not coming up on boot. Power cycling the port
corresponding to the MST monitor's branch device and resending the message
fixes the issue. I am not entirely sure if this is specific to my setup.
However, as the power state is toggled conditionally on LINK_ADDRESS
timeouts, this should not affect the working cases.
Cc: Lyude <ly...@redhat.com>
Cc: Dave Airlie <airl...@redhat.com>
Cc: Jani Nikula <jani.nik...@intel.com>
Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandi...@intel.com>
---
drivers/gpu/drm/drm_dp_mst_topology.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
b/drivers/gpu/drm/drm_dp_mst_topology.c
index 70dcfa58d3c2..e06defcdcf18 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1596,8 +1596,9 @@ static void drm_dp_send_link_address(struct
drm_dp_mst_topology_mgr *mgr,
int len;
struct drm_dp_sideband_msg_tx *txmsg;
int ret;
+ int attempts = 5;
- txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
+retry: txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
if (!txmsg)
return;
@@ -1635,9 +1636,17 @@ static void drm_dp_send_link_address(struct
drm_dp_mst_topology_mgr *mgr,
}
(*mgr->cbs->hotplug)(mgr);
}
+ } else if (attempts--) {
+ kfree(txmsg);
+ drm_dp_send_power_updown_phy(mstb->mgr, mstb->port_parent,
+ false);
+ drm_dp_send_power_updown_phy(mstb->mgr, mstb->port_parent,
+ true);
+ DRM_DEBUG_KMS("link address failed %d, retrying\n", ret);
+ goto retry;
} else {
mstb->link_address_sent = false;
- DRM_DEBUG_KMS("link address failed %d\n", ret);
+ DRM_DEBUG_KMS("link address failed %d, giving up\n", ret);
}
kfree(txmsg);
--
2.11.0
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