diff options
| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2015-06-22 17:31:59 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-08-03 09:29:08 -0700 |
| commit | c8f84f037a61845643f4f86bf9ba49494a65e2c0 (patch) | |
| tree | 2ca97bc832ed8fdd4238a8e0ec88a22a23da200b /drivers/gpu | |
| parent | e60bd2d701a57d0cd9fe53de5e1426af03874c0d (diff) | |
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@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/drm_dp_mst_topology.c | 24 |
1 files 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 9dce95331624..778bbb6425b8 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1200,7 +1200,7 @@ 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; @@ -1215,17 +1215,31 @@ 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, |