[3.19.y-ckt stable] Patch "drm/dp/mst: make sure mst_primary mstb is valid in work function" has been added to staging queue
Kamal Mostafa
kamal at canonical.com
Thu Jul 16 01:01:20 UTC 2015
This is a note to let you know that I have just added a patch titled
drm/dp/mst: make sure mst_primary mstb is valid in work function
to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree
which can be found at:
http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue
This patch is scheduled to be released in version 3.19.y-ckt4.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
------
>From 4bec1c3c44a859779e1cd7bc582c7718b983fae0 Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter at ffwll.ch>
Date: Mon, 22 Jun 2015 17:31:59 +1000
Subject: drm/dp/mst: make sure mst_primary mstb is valid in work function
commit 9254ec496a1dbdddeab50021a8138dc627a8166a upstream.
This validates the mst_primary under the lock, and then calls
into the check and send function. This makes the code a lot
easier to understand the locking rules in.
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Signed-off-by: Dave Airlie <airlied at redhat.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
drivers/gpu/drm/drm_dp_mst_topology.c | 24 +++++++++++++++++++-----
1 file changed, 19 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 9a5b687..e0da405 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1185,7 +1185,7 @@ static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *m
struct drm_dp_mst_branch *mstb)
{
struct drm_dp_mst_port *port;
-
+ struct drm_dp_mst_branch *mstb_child;
if (!mstb->link_address_sent) {
drm_dp_send_link_address(mgr, mstb);
mstb->link_address_sent = true;
@@ -1200,17 +1200,31 @@ static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *m
if (!port->available_pbn)
drm_dp_send_enum_path_resources(mgr, mstb, port);
- if (port->mstb)
- drm_dp_check_and_send_link_address(mgr, port->mstb);
+ if (port->mstb) {
+ mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
+ if (mstb_child) {
+ drm_dp_check_and_send_link_address(mgr, mstb_child);
+ drm_dp_put_mst_branch_device(mstb_child);
+ }
+ }
}
}
static void drm_dp_mst_link_probe_work(struct work_struct *work)
{
struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
+ struct drm_dp_mst_branch *mstb;
- drm_dp_check_and_send_link_address(mgr, mgr->mst_primary);
-
+ mutex_lock(&mgr->lock);
+ mstb = mgr->mst_primary;
+ if (mstb) {
+ kref_get(&mstb->kref);
+ }
+ mutex_unlock(&mgr->lock);
+ if (mstb) {
+ drm_dp_check_and_send_link_address(mgr, mstb);
+ drm_dp_put_mst_branch_device(mstb);
+ }
}
static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
--
1.9.1
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