From patchwork Thu Jun 2 20:17:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lyude Paul X-Patchwork-Id: 12868126 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A6B3EC43334 for ; Thu, 2 Jun 2022 20:18:20 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 09ADD113164; Thu, 2 Jun 2022 20:18:20 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2D08411315B for ; Thu, 2 Jun 2022 20:18:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1654201097; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=AeiolL2bTO529ilMOcovMOAtIExzOmMLAEaBQmNVSso=; b=buILzPW4tuECVMzuhoxvx2ARTLHt7/r/Rur4oZuBz1LWPoJIBjoWXzhb8lAdFco5I41vFe jiHkWNpWaD5iabbo4dQsHKMKhzs+4wcPB1XfrbnaDQfIsee1xEVnzmGMIisPByKJugybtD Uz4WZEVj8NNejBRrh23L5Df2iIsOGHY= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-278-c_gSzuF1NuGdLjrjELcKoQ-1; Thu, 02 Jun 2022 16:18:14 -0400 X-MC-Unique: c_gSzuF1NuGdLjrjELcKoQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E1E6610726B8; Thu, 2 Jun 2022 20:18:09 +0000 (UTC) Received: from emerald.redhat.com (unknown [10.22.34.8]) by smtp.corp.redhat.com (Postfix) with ESMTP id BD6BC414A7E7; Thu, 2 Jun 2022 20:18:08 +0000 (UTC) From: Lyude Paul To: dri-devel@lists.freedesktop.org Subject: [PATCH 1/3] drm/display/dp_mst: Don't validate port refs in drm_dp_check_and_send_link_address() Date: Thu, 2 Jun 2022 16:17:55 -0400 Message-Id: <20220602201757.30431-2-lyude@redhat.com> In-Reply-To: <20220602201757.30431-1-lyude@redhat.com> References: <20220602201757.30431-1-lyude@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: David Airlie , open list , Jani Nikula , Thomas Zimmermann , Wayne Lin , Bhawanpreet Lakha , Rajkumar Subbiah Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Drive-by cleanup, we don't need to validate the port references here as we already previously went through the effort of refactoring things such that we're guaranteed to be able to access ->mstb and ->port safely from drm_dp_check_and_send_link_address(), since the only two places in the codebase that drop an MST reference in such a way that it would remove it from the topology are both protected under probe_lock. Thanks for that, past Lyude! Signed-off-by: Lyude Paul Reviewed-by: Wayne Lin --- drivers/gpu/drm/display/drm_dp_mst_topology.c | 22 +++++-------------- 1 file changed, 6 insertions(+), 16 deletions(-) diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c index 67b3b9697da7..d84673b3294b 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -2666,24 +2666,14 @@ static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mg } list_for_each_entry(port, &mstb->ports, next) { - struct drm_dp_mst_branch *mstb_child = NULL; - - if (port->input || !port->ddps) + if (port->input || !port->ddps || !port->mstb) continue; - if (port->mstb) - mstb_child = drm_dp_mst_topology_get_mstb_validated( - mgr, port->mstb); - - if (mstb_child) { - ret = drm_dp_check_and_send_link_address(mgr, - mstb_child); - drm_dp_mst_topology_put_mstb(mstb_child); - if (ret == 1) - changed = true; - else if (ret < 0) - return ret; - } + ret = drm_dp_check_and_send_link_address(mgr, port->mstb); + if (ret == 1) + changed = true; + else if (ret < 0) + return ret; } return changed;