[Intel-gfx] Patch "drm/dp_mst: Don't report ports connected if nothing is attached to them" has been added to the 5.10-stable tree

[gregkh at linuxfoundation.org]

This is a note to let you know that I've just added the patch titled

    drm/dp_mst: Don't report ports connected if nothing is attached to them

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-don-t-report-ports-connected-if-nothing-is-attached-to-them.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 at vger.kernel.org> know about it.


>From 873e5bb9fbd99e4a26c448b5c7af942a6d7aa60d Mon Sep 17 00:00:00 2001
From: Imre Deak <imre.deak at intel.com>
Date: Mon, 1 Feb 2021 14:01:42 +0200
Subject: drm/dp_mst: Don't report ports connected if nothing is attached to them

From: Imre Deak <imre.deak at intel.com>

commit 873e5bb9fbd99e4a26c448b5c7af942a6d7aa60d upstream.

Reporting a port as connected if nothing is attached to them leads to
any i2c transactions on this port trying to use an uninitialized i2c
adapter, fix this.

Let's account for this case even if branch devices have no good reason
to report a port as plugged with their peer device type set to 'none'.

Fixes: db1a07956968 ("drm/dp_mst: Handle SST-only branch device case")
References: https://gitlab.freedesktop.org/drm/intel/-/issues/2987
References: https://gitlab.freedesktop.org/drm/intel/-/issues/1963
Cc: Wayne Lin <Wayne.Lin at amd.com>
Cc: Lyude Paul <lyude at redhat.com>
Cc: <stable at vger.kernel.org> # v5.5+
Cc: intel-gfx at lists.freedesktop.org
Signed-off-by: Imre Deak <imre.deak at intel.com>
Reviewed-by: Lyude Paul <lyude at redhat.com>
Reported-by: Thiago Macieira <gitlab at gitlab.freedesktop.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210201120145.350258-1-imre.deak@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 drivers/gpu/drm/drm_dp_mst_topology.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -4224,6 +4224,7 @@ drm_dp_mst_detect_port(struct drm_connec
 
 	switch (port->pdt) {
 	case DP_PEER_DEVICE_NONE:
+		break;
 	case DP_PEER_DEVICE_MST_BRANCHING:
 		if (!port->mcs)
 			ret = connector_status_connected;


Patches currently in stable-queue which might be from imre.deak at intel.com are

queue-5.10/drm-dp_mst-don-t-report-ports-connected-if-nothing-is-attached-to-them.patch
queue-5.10/drm-i915-tgl-make-sure-typec-fia-is-powered-up-when-initializing-it.patch