From patchwork Mon Nov 14 22:17:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lyude Paul X-Patchwork-Id: 13042883 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 E478AC4332F for ; Mon, 14 Nov 2022 22:19:04 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 5D1B210E33C; Mon, 14 Nov 2022 22:19:00 +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 3D5B410E339 for ; Mon, 14 Nov 2022 22:18:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1668464327; 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=O/M4W3uv7gwCZ1OdzG4UeM3eO9Q4aCQx77adsACSB0c=; b=dJ5iQu48CKb9ClMtg50GY2b4Mt277uWPxCXzNqD44W9nyt7rosvSLhWHc5QyEdJ/t83OhH 8TV529gjx9l2fyORHzd3GjIoa0Wq+mTANwcfmIpoRGxm6mrSHeZmWhhZHGklTs6dEZDBOG /DI7mxeQPoWWKiv7cEWgJe0nNn0hQEI= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-646-xk6AjHqqOZyE6qJvTWmfFg-1; Mon, 14 Nov 2022 17:18:44 -0500 X-MC-Unique: xk6AjHqqOZyE6qJvTWmfFg-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 07A692A59559; Mon, 14 Nov 2022 22:18:43 +0000 (UTC) Received: from emerald.lyude.net (unknown [10.22.18.150]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4761E4022C3; Mon, 14 Nov 2022 22:18:42 +0000 (UTC) From: Lyude Paul To: amd-gfx@lists.freedesktop.org Subject: [PATCH v2 4/4] drm/amdgpu/dm/dp_mst: Don't grab mst_mgr->lock when computing DSC state Date: Mon, 14 Nov 2022 17:17:55 -0500 Message-Id: <20221114221754.385090-5-lyude@redhat.com> In-Reply-To: <20221114221754.385090-1-lyude@redhat.com> References: <20221114221754.385090-1-lyude@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 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: "open list:DRM DRIVERS" , Leo Li , David Francis , "Pan, Xinhui" , Rodrigo Siqueira , Roman Li , stable@vger.kernel.org, Nicholas Kazlauskas , Wenjing Liu , Fangzhi Zuo , hersen wu , Hamza Mahfooz , Wayne Lin , Alex Deucher , Mikita Lipski , =?utf-8?q?Christian_K=C3=B6nig?= , open list Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Now that we've fixed the issue with using the incorrect topology manager, we're actually grabbing the topology manager's lock - and consequently deadlocking. Luckily for us though, there's actually nothing in AMD's DSC state computation code that really should need this lock. The one exception is the mutex_lock() in dm_dp_mst_is_port_support_mode(), however we grab no locks beneath &mgr->lock there so that should be fine to leave be. Signed-off-by: Lyude Paul Gitlab issue: https://gitlab.freedesktop.org/drm/amd/-/issues/2171 Fixes: 8c20a1ed9b4f ("drm/amd/display: MST DSC compute fair share") Cc: # v5.6+ --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c index 5196c9a0e432d..59648f5ffb59d 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c @@ -1148,10 +1148,8 @@ int compute_mst_dsc_configs_for_state(struct drm_atomic_state *state, continue; mst_mgr = aconnector->port->mgr; - mutex_lock(&mst_mgr->lock); ret = compute_mst_dsc_configs_for_link(state, dc_state, stream->link, vars, mst_mgr, &link_vars_start_index); - mutex_unlock(&mst_mgr->lock); if (ret != 0) return ret; @@ -1208,10 +1206,8 @@ static int pre_compute_mst_dsc_configs_for_state(struct drm_atomic_state *state, continue; mst_mgr = aconnector->port->mgr; - mutex_lock(&mst_mgr->lock); ret = compute_mst_dsc_configs_for_link(state, dc_state, stream->link, vars, mst_mgr, &link_vars_start_index); - mutex_unlock(&mst_mgr->lock); if (ret != 0) return ret;