From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D343FC7618F for ; Thu, 18 Jul 2019 01:45:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B335721874 for ; Thu, 18 Jul 2019 01:45:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389314AbfGRBpA (ORCPT ); Wed, 17 Jul 2019 21:45:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40142 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389252AbfGRBoy (ORCPT ); Wed, 17 Jul 2019 21:44:54 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 208C63082E42; Thu, 18 Jul 2019 01:44:54 +0000 (UTC) Received: from whitewolf.redhat.com (ovpn-120-112.rdu2.redhat.com [10.10.120.112]) by smtp.corp.redhat.com (Postfix) with ESMTP id 96F3419C67; Thu, 18 Jul 2019 01:44:52 +0000 (UTC) From: Lyude Paul To: dri-devel@lists.freedesktop.org Cc: Juston Li , Imre Deak , =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , Harry Wentland , Maarten Lankhorst , Maxime Ripard , Sean Paul , David Airlie , Daniel Vetter , linux-kernel@vger.kernel.org Subject: [PATCH 20/26] drm/dp_mst: Don't forget to update port->input in drm_dp_mst_handle_conn_stat() Date: Wed, 17 Jul 2019 21:42:43 -0400 Message-Id: <20190718014329.8107-21-lyude@redhat.com> In-Reply-To: <20190718014329.8107-1-lyude@redhat.com> References: <20190718014329.8107-1-lyude@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Thu, 18 Jul 2019 01:44:54 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This probably hasn't caused any problems up until now since it's probably nearly impossible to encounter this in the wild, however if we were to receive a connection status notification from the MST hub after resume while we're in the middle of reprobing the link addresses for a topology then there's a much larger chance that a port could have changed from being an output port to input port (or vice versa). If we forget to update this bit of information, we'll potentially ignore a valid PDT change on a downstream port because we think it's an input port. So, make sure we read the input_port field in connection status notifications in drm_dp_mst_handle_conn_stat() to prevent this from happening once we've implemented suspend/resume reprobing. Cc: Juston Li Cc: Imre Deak Cc: Ville Syrjälä Cc: Harry Wentland Signed-off-by: Lyude Paul --- drivers/gpu/drm/drm_dp_mst_topology.c | 51 +++++++++++++++++++-------- 1 file changed, 37 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index dffd80f31537..126db36c9337 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1989,18 +1989,23 @@ static void drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb, struct drm_dp_connection_status_notify *conn_stat) { - struct drm_device *dev = mstb->mgr->dev; + struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; + struct drm_device *dev = mgr->dev; struct drm_dp_mst_port *port; - int old_ddps; - bool dowork = false; + struct drm_connector *connector_to_destroy = NULL; + int old_ddps, ret; + u8 new_pdt; + bool dowork = false, create_connector = false; port = drm_dp_get_port(mstb, conn_stat->port_number); if (!port) return; + mutex_lock(&port->lock); drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); old_ddps = port->ddps; + port->input = conn_stat->input_port; port->mcs = conn_stat->message_capability_status; port->ldps = conn_stat->legacy_device_plug_status; port->ddps = conn_stat->displayport_device_plug_status; @@ -2013,23 +2018,41 @@ drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb, } } - if (!port->input) { - int ret = drm_dp_port_set_pdt(port, - conn_stat->peer_device_type); - if (ret == 1) { - dowork = true; - } else if (ret < 0) { - DRM_ERROR("Failed to change PDT for port %p: %d\n", - port, ret); - dowork = false; - } + new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type; + + ret = drm_dp_port_set_pdt(port, new_pdt); + if (ret == 1) { + dowork = true; + } else if (ret < 0) { + DRM_ERROR("Failed to change PDT for port %p: %d\n", + port, ret); + dowork = false; + } + + /* + * We unset port->connector before dropping connection_mutex so that + * there's no chance any of the atomic MST helpers can accidentally + * associate a to-be-destroyed connector with a port. + */ + if (port->connector && port->input) { + connector_to_destroy = port->connector; + port->connector = NULL; + } else if (!port->connector && !port->input) { + create_connector = true; } drm_modeset_unlock(&dev->mode_config.connection_mutex); + + if (connector_to_destroy) + mgr->cbs->destroy_connector(mgr, connector_to_destroy); + else if (create_connector) + drm_dp_mst_port_add_connector(mstb, port); + + mutex_unlock(&port->lock); + drm_dp_mst_topology_put_port(port); if (dowork) queue_work(system_long_wq, &mstb->mgr->work); - } static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr, -- 2.21.0