From d29333cf5cd7594bd9a6bac10cbb4ec7079dc9a3 Mon Sep 17 00:00:00 2001 From: Lyude Paul Date: Sun, 10 Mar 2019 18:59:10 -0400 Subject: [PATCH] drm/dp_mst: Remove PDT teardown in drm_dp_destroy_port() and refactor MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This will allow us to add some locking for port->* members, in particular the PDT and ->connector, which can't be done from drm_dp_destroy_port() since we don't know what locks the caller might be holding. Note that we already do this in delayed_destroy_work (renamed from destroy_connector_work in this patch) for ports, we're just making it so mstbs are also destroyed in this worker. Changes since v2: * Clarify commit message Changes since v4: * Clarify commit message more Cc: Juston Li Cc: Imre Deak Cc: Ville Syrjälä Cc: Harry Wentland Cc: Daniel Vetter Reviewed-by: Sean Paul Signed-off-by: Lyude Paul Link: https://patchwork.freedesktop.org/patch/msgid/20191022023641.8026-3-lyude@redhat.com --- drivers/gpu/drm/drm_dp_mst_topology.c | 42 +++++++++++---------------- 1 file changed, 17 insertions(+), 25 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index bbda316f5a0d..82d6c0f9395d 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1510,31 +1510,22 @@ static void drm_dp_destroy_port(struct kref *kref) container_of(kref, struct drm_dp_mst_port, topology_kref); struct drm_dp_mst_topology_mgr *mgr = port->mgr; - if (!port->input) { - kfree(port->cached_edid); - - /* - * The only time we don't have a connector - * on an output port is if the connector init - * fails. - */ - if (port->connector) { - /* we can't destroy the connector here, as - * we might be holding the mode_config.mutex - * from an EDID retrieval */ - - mutex_lock(&mgr->delayed_destroy_lock); - list_add(&port->next, &mgr->destroy_port_list); - mutex_unlock(&mgr->delayed_destroy_lock); - schedule_work(&mgr->delayed_destroy_work); - return; - } - /* 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; + /* There's nothing that needs locking to destroy an input port yet */ + if (port->input) { + drm_dp_mst_put_port_malloc(port); + return; } - drm_dp_mst_put_port_malloc(port); + + kfree(port->cached_edid); + + /* + * we can't destroy the connector here, as we might be holding the + * mode_config.mutex from an EDID retrieval + */ + mutex_lock(&mgr->delayed_destroy_lock); + list_add(&port->next, &mgr->destroy_port_list); + mutex_unlock(&mgr->delayed_destroy_lock); + schedule_work(&mgr->delayed_destroy_work); } /** @@ -3981,7 +3972,8 @@ static void drm_dp_tx_work(struct work_struct *work) static inline void drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port) { - port->mgr->cbs->destroy_connector(port->mgr, port->connector); + if (port->connector) + port->mgr->cbs->destroy_connector(port->mgr, port->connector); drm_dp_port_teardown_pdt(port, port->pdt); port->pdt = DP_PEER_DEVICE_NONE;