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=-15.8 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 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 6E5C1C433DB for ; Wed, 17 Feb 2021 12:34:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 332E264E0F for ; Wed, 17 Feb 2021 12:34:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232689AbhBQMdy (ORCPT ); Wed, 17 Feb 2021 07:33:54 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:50488 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232457AbhBQMdt (ORCPT ); Wed, 17 Feb 2021 07:33:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1613565142; 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=kq5DugD1inTY+nk/xI8ba0kERqE5bPFWx/0JoZ2/L1c=; b=Xz4xeu8Esszy0Pa4CvQRrSNOrWyqVh3ww/sNKercFPUc7uNydXzCl0y6OtNELJonD+fvVi meVdKkRNFWn7VIhQH80/5pLF4sa0Mu3bVmH+iblpMnJkgbnrnIIMJuyUcvGtgebqoTKkQN 7mmv9w4xW3i07xM6vvj40n2PSwReDGk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-221-cWWPjsRnOuCH3UgO48axpQ-1; Wed, 17 Feb 2021 07:32:20 -0500 X-MC-Unique: cWWPjsRnOuCH3UgO48axpQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 13EE380196C; Wed, 17 Feb 2021 12:32:19 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-114-184.ams2.redhat.com [10.36.114.184]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 7DB195D9C2; Wed, 17 Feb 2021 12:32:15 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id 1E22918003B5; Wed, 17 Feb 2021 13:32:14 +0100 (CET) From: Gerd Hoffmann To: dri-devel@lists.freedesktop.org Cc: Gerd Hoffmann , Dave Airlie , David Airlie , Daniel Vetter , Thomas Zimmermann , virtualization@lists.linux-foundation.org (open list:DRM DRIVER FOR QXL VIRTUAL GPU), spice-devel@lists.freedesktop.org (open list:DRM DRIVER FOR QXL VIRTUAL GPU), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v2 04/11] drm/qxl: fix lockdep issue in qxl_alloc_release_reserved Date: Wed, 17 Feb 2021 13:32:06 +0100 Message-Id: <20210217123213.2199186-5-kraxel@redhat.com> In-Reply-To: <20210217123213.2199186-1-kraxel@redhat.com> References: <20210217123213.2199186-1-kraxel@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Call qxl_bo_unpin (which does a reservation) without holding the release_mutex lock. Fixes lockdep (correctly) warning on a possible deadlock. Fixes: 65ffea3c6e73 ("drm/qxl: unpin release objects") Signed-off-by: Gerd Hoffmann --- drivers/gpu/drm/qxl/qxl_release.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/qxl/qxl_release.c b/drivers/gpu/drm/qxl/qxl_release.c index 716d706ca7f0..f5845c96d414 100644 --- a/drivers/gpu/drm/qxl/qxl_release.c +++ b/drivers/gpu/drm/qxl/qxl_release.c @@ -283,7 +283,7 @@ int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size, int type, struct qxl_release **release, struct qxl_bo **rbo) { - struct qxl_bo *bo; + struct qxl_bo *bo, *free_bo = NULL; int idr_ret; int ret = 0; union qxl_release_info *info; @@ -315,8 +315,7 @@ int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size, mutex_lock(&qdev->release_mutex); if (qdev->current_release_bo_offset[cur_idx] + 1 >= releases_per_bo[cur_idx]) { - qxl_bo_unpin(qdev->current_release_bo[cur_idx]); - qxl_bo_unref(&qdev->current_release_bo[cur_idx]); + free_bo = qdev->current_release_bo[cur_idx]; qdev->current_release_bo_offset[cur_idx] = 0; qdev->current_release_bo[cur_idx] = NULL; } @@ -324,6 +323,10 @@ int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size, ret = qxl_release_bo_alloc(qdev, &qdev->current_release_bo[cur_idx], priority); if (ret) { mutex_unlock(&qdev->release_mutex); + if (free_bo) { + qxl_bo_unpin(free_bo); + qxl_bo_unref(&free_bo); + } qxl_release_free(qdev, *release); return ret; } @@ -339,6 +342,10 @@ int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size, *rbo = bo; mutex_unlock(&qdev->release_mutex); + if (free_bo) { + qxl_bo_unpin(free_bo); + qxl_bo_unref(&free_bo); + } ret = qxl_release_list_add(*release, bo); qxl_bo_unref(&bo); -- 2.29.2