4.1-stable review patch. If anyone has any objections, please let me know.
------------------ From: Daniel Vetter <[email protected]> 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 <[email protected]> Reviewed-by: Daniel Vetter <[email protected]> Signed-off-by: Dave Airlie <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/gpu/drm/drm_dp_mst_topology.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) --- 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_a 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_a 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, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
