Patch "drm/dp/mst: take lock around looking up the branch device on hpd irq" has been added to the 4.1-stable tree

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

drm/dp/mst: take lock around looking up the branch device on hpd irq

to the 4.1-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-take-lock-around-looking-up-the-branch-device-on-hpd-irq.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Dave Airlie <[email protected]>
Date: Mon, 22 Jun 2015 14:40:44 +1000
Subject: drm/dp/mst: take lock around looking up the branch device on hpd irq

From: Dave Airlie <[email protected]>

commit 9eb1e57f564d4e6e10991402726cc83fe0b9172f upstream.

If we are doing an MST transaction and we've gotten HPD and we lookup the device from the incoming msg, we should take the mgr lock around it, so that mst_primary and mstb->ports are valid.

---
 drivers/gpu/drm/drm_dp_mst_topology.c |    3 +++
 1 file changed, 3 insertions(+)

@@ -1171,6 +1171,8 @@ static struct drm_dp_mst_branch *drm_dp_
 	struct drm_dp_mst_port *port;
 	int i;
 	/* find the port by iterating down */
+
+	mutex_lock(&mgr->lock);
 	mstb = mgr->mst_primary;
 
 	for (i = 0; i < lct - 1; i++) {

@@ -1190,6 +1192,7 @@ static struct drm_dp_mst_branch *drm_dp_
 		}
 	}
 	kref_get(&mstb->kref);
+	mutex_unlock(&mgr->lock);
 	return mstb;
 }
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.1/drm-vgem-set-unique-to-vgem.patch queue-4.1/drm-dp-mst-take-lock-around-looking-up-the-branch-device-on-hpd-irq.patch queue-4.1/drm-dp-mst-make-sure-mst_primary-mstb-is-valid-in-work-function.patch queue-4.1/drm-qxl-do-not-leak-memory-if-qxl_release_list_add-fails.patch queue-4.1/drm-qxl-do-not-cause-spice-server-to-clean-our-objects.patch queue-4.1/drm-dp-mst-close-deadlock-in-connector-destruction.patch