From patchwork Mon Jul 19 14:50:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 480817 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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 45908C07E95 for ; Mon, 19 Jul 2021 15:54:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2DFCE61279 for ; Mon, 19 Jul 2021 15:54:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346082AbhGSPNi (ORCPT ); Mon, 19 Jul 2021 11:13:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:47200 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345619AbhGSPMJ (ORCPT ); Mon, 19 Jul 2021 11:12:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 590716128E; Mon, 19 Jul 2021 15:52:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626709956; bh=yaTQYHirmBKbG37mh1K7PYcOY8yl4a4MLQ1mreivnoc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R8oevDr7qMofJyfIIMcnyTqZ+PYDWsiqNsdOga/oTO5T3hvHz0lnnIyO3JD1NL3X8 j3mGp7CstbFFqw2f23qW/P8MesJIb6NtAAy7ufwfgEUR+SV9SUMQ1e4RCtfxk7nKns 4UhBi6/1EebSvzovuBqJp8A3/JTZnnehQ11IjwtY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wayne Lin , Lyude Paul Subject: [PATCH 5.10 016/243] drm/dp_mst: Avoid to mess up payload table by ports in stale topology Date: Mon, 19 Jul 2021 16:50:45 +0200 Message-Id: <20210719144941.445588771@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144940.904087935@linuxfoundation.org> References: <20210719144940.904087935@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Wayne Lin commit 3769e4c0af5b82c8ea21d037013cb9564dfaa51f upstream. [Why] After unplug/hotplug hub from the system, userspace might start to clear stale payloads gradually. If we call drm_dp_mst_deallocate_vcpi() to release stale VCPI of those ports which are not relating to current topology, we have chane to wrongly clear active payload table entry for current topology. E.g. We have allocated VCPI 1 in current payload table and we call drm_dp_mst_deallocate_vcpi() to clean VCPI 1 in stale topology. In drm_dp_mst_deallocate_vcpi(), it will call drm_dp_mst_put_payload_id() tp put VCPI 1 and which means ID 1 is available again. Thereafter, if we want to allocate a new payload stream, it will find ID 1 is available by drm_dp_mst_assign_payload_id(). However, ID 1 is being used [How] Check target sink is relating to current topology or not before doing any payload table update. Searching upward to find the target sink's relevant root branch device. If the found root branch device is not the same root of current topology, don't update payload table. Changes since v1: * Change debug macro to use drm_dbg_kms() instead * Amend the commit message to add Cc tag. Signed-off-by: Wayne Lin Cc: stable@vger.kernel.org Signed-off-by: Lyude Paul Link: https://patchwork.freedesktop.org/patch/msgid/20210616035501.3776-3-Wayne.Lin@amd.com Reviewed-by: Lyude Paul Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_dp_mst_topology.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -94,6 +94,9 @@ static int drm_dp_mst_register_i2c_bus(s static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port); static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr); +static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port, + struct drm_dp_mst_branch *branch); + #define DBG_PREFIX "[dp_mst]" #define DP_STR(x) [DP_ ## x] = #x @@ -3362,6 +3365,7 @@ int drm_dp_update_payload_part1(struct d struct drm_dp_mst_port *port; int i, j; int cur_slots = 1; + bool skip; mutex_lock(&mgr->payload_lock); for (i = 0; i < mgr->max_payloads; i++) { @@ -3376,6 +3380,14 @@ int drm_dp_update_payload_part1(struct d port = container_of(vcpi, struct drm_dp_mst_port, vcpi); + mutex_lock(&mgr->lock); + skip = !drm_dp_mst_port_downstream_of_branch(port, mgr->mst_primary); + mutex_unlock(&mgr->lock); + + if (skip) { + drm_dbg_kms("Virtual channel %d is not in current topology\n", i); + continue; + } /* Validated ports don't matter if we're releasing * VCPI */ @@ -3475,6 +3487,7 @@ int drm_dp_update_payload_part2(struct d struct drm_dp_mst_port *port; int i; int ret = 0; + bool skip; mutex_lock(&mgr->payload_lock); for (i = 0; i < mgr->max_payloads; i++) { @@ -3484,6 +3497,13 @@ int drm_dp_update_payload_part2(struct d port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi); + mutex_lock(&mgr->lock); + skip = !drm_dp_mst_port_downstream_of_branch(port, mgr->mst_primary); + mutex_unlock(&mgr->lock); + + if (skip) + continue; + DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state); if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) { ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]); @@ -4565,9 +4585,18 @@ EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slot void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) { + bool skip; + if (!port->vcpi.vcpi) return; + mutex_lock(&mgr->lock); + skip = !drm_dp_mst_port_downstream_of_branch(port, mgr->mst_primary); + mutex_unlock(&mgr->lock); + + if (skip) + return; + drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi); port->vcpi.num_slots = 0; port->vcpi.pbn = 0;