From patchwork Wed Apr 20 11:15:22 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefano Stabellini X-Patchwork-Id: 8888821 Return-Path: X-Original-To: patchwork-qemu-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 224AA9F1D3 for ; Wed, 20 Apr 2016 11:16:18 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7D387201B4 for ; Wed, 20 Apr 2016 11:16:17 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CB06920165 for ; Wed, 20 Apr 2016 11:16:16 +0000 (UTC) Received: from localhost ([::1]:47367 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1asq7E-0006Kh-5k for patchwork-qemu-devel@patchwork.kernel.org; Wed, 20 Apr 2016 07:16:16 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34976) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1asq6k-0005d8-UO for qemu-devel@nongnu.org; Wed, 20 Apr 2016 07:15:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1asq6g-0004ER-ST for qemu-devel@nongnu.org; Wed, 20 Apr 2016 07:15:46 -0400 Received: from mail.kernel.org ([198.145.29.136]:55300) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1asq6g-0004EM-MY for qemu-devel@nongnu.org; Wed, 20 Apr 2016 07:15:42 -0400 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B0E4C201B4; Wed, 20 Apr 2016 11:15:40 +0000 (UTC) Received: from localhost.localdomain (107.238.189.80.dyn.plus.net [80.189.238.107]) (using TLSv1.2 with cipher AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D4AFE20165; Wed, 20 Apr 2016 11:15:38 +0000 (UTC) From: Stefano Stabellini To: peter.maydell@linaro.org Date: Wed, 20 Apr 2016 12:15:22 +0100 Message-Id: <1461150922-14509-1-git-send-email-sstabellini@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: References: X-Virus-Scanned: ClamAV using ClamSMTP X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 198.145.29.136 Subject: [Qemu-devel] [PULL for-2.6 1/1] xenfb: use the correct condition to avoid excessive looping X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: xen-devel@lists.xensource.com, sstabellini@kernel.org, Wei Liu , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Wei Liu In commit ac0487e1 ("xenfb.c: avoid expensive loops when prod <= out_cons"), ">=" was used. In fact, a full ring is a legit state. Correct the test to use ">". Reported-by: "Hao, Xudong" Signed-off-by: Wei Liu Tested-by: "Hao, Xudong" Acked-by: Anthony Perard Signed-off-by: Stefano Stabellini --- hw/display/xenfb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/display/xenfb.c b/hw/display/xenfb.c index 40b096a..9866dfd 100644 --- a/hw/display/xenfb.c +++ b/hw/display/xenfb.c @@ -775,7 +775,7 @@ static void xenfb_handle_events(struct XenFB *xenfb) prod = page->out_prod; out_cons = page->out_cons; - if (prod - out_cons >= XENFB_OUT_RING_LEN) { + if (prod - out_cons > XENFB_OUT_RING_LEN) { return; } xen_rmb(); /* ensure we see ring contents up to prod */