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=-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=unavailable 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 2160DC07E95 for ; Mon, 19 Jul 2021 17:28:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EE74A610D0 for ; Mon, 19 Jul 2021 17:28:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347831AbhGSQsB (ORCPT ); Mon, 19 Jul 2021 12:48:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:38166 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348212AbhGSPYj (ORCPT ); Mon, 19 Jul 2021 11:24:39 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 88DE26140E; Mon, 19 Jul 2021 16:03:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626710590; bh=YpiV6X3H08q/4trbmkrSG6VkxvyotsF79iM7KJklwmw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YOsfP2r5vwvGfUKMbzTFrWK5rd3kfj6aLoufeMY7vY5fNwXLotEm8QxY39H1X1XvA h5TrXs+xYszA4DQoZrjMMuJA4sn7QEE118iNjPyRZxFttsUSB6BKu5po9eQ39ez3e0 l8a4MYRfMieqCWLe4K02nYuUe/OaUVTmHONv87UU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wayne Lin , Lyude Paul Subject: [PATCH 5.13 035/351] drm/dp_mst: Avoid to mess up payload table by ports in stale topology Date: Mon, 19 Jul 2021 16:49:41 +0200 Message-Id: <20210719144945.687164541@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144944.537151528@linuxfoundation.org> References: <20210719144944.537151528@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 @@ -3360,6 +3363,7 @@ 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++) { @@ -3374,6 +3378,14 @@ 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 */ @@ -3473,6 +3485,7 @@ 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++) { @@ -3482,6 +3495,13 @@ 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]); @@ -4561,9 +4581,18 @@ 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;