Patch "drm/dp/mst: Clear port->pdt when tearing down the i2c adapter" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

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

    drm/dp/mst: Clear port->pdt when tearing down the i2c adapter

to the 4.4-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-clear-port-pdt-when-tearing-down-the-i2c-adapter.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 36e3fa6a38e135e9478a2f75dec9bf6ff1e6480e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Wed, 26 Oct 2016 16:30:33 +0300
Subject: drm/dp/mst: Clear port->pdt when tearing down the i2c adapter
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From: Ville Syrjälä <ville.syrjala@linux.intel.com>

commit 36e3fa6a38e135e9478a2f75dec9bf6ff1e6480e upstream.

The i2c adapter is only relevant for some peer device types, so
let's clear the pdt if it's still the same as the old_pdt when we
tear down the i2c adapter.

I don't really like this design pattern of updating port->whatever
before doing the accompanying changes and passing around old_whatever
to figure stuff out. Would make much more sense to me to the pass the
new value around and only update the port->whatever when things are
consistent. But let's try to work with what we have right now.

Quoting a follow-up from Ville:

"And naturally I forgot to amend the commit message w.r.t. this guy
[the change in drm_dp_destroy_port].  We don't really need to do this
here, but I figured I'd try to be a bit more consistent by having it,
just to avoid accidental mistakes if/when someone changes this stuff
again later."

v2: Clear port->pdt in the caller, if needed (Daniel)

Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Carlos Santa <carlos.santa@intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Tested-by: Carlos Santa <carlos.santa@intel.com> (v1)
Tested-by: Kirill A. Shutemov <kirill@shutemov.name> (v1)
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97666
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1477488633-16544-1-git-send-email-ville.syrjala@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/drm_dp_mst_topology.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -909,6 +909,7 @@ static void drm_dp_destroy_port(struct k
 		/* no need to clean up vcpi
 		 * as if we have no connector we never setup a vcpi */
 		drm_dp_port_teardown_pdt(port, port->pdt);
+		port->pdt = DP_PEER_DEVICE_NONE;
 	}
 	kfree(port);
 }
@@ -2872,6 +2873,7 @@ static void drm_dp_destroy_connector_wor
 		mgr->cbs->destroy_connector(mgr, port->connector);
 
 		drm_dp_port_teardown_pdt(port, port->pdt);
+		port->pdt = DP_PEER_DEVICE_NONE;
 
 		if (!port->input && port->vcpi.vcpi > 0) {
 			drm_dp_mst_reset_vcpi_slots(mgr, port);


Patches currently in stable-queue which might be from ville.syrjala@linux.intel.com are

queue-4.4/drm-dp-mst-clear-port-pdt-when-tearing-down-the-i2c-adapter.patch