From patchwork Sat May 25 15:12:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?C=C3=A9dric_Le_Goater?= X-Patchwork-Id: 10960889 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0D2A61575 for ; Sat, 25 May 2019 15:38:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EF846286F1 for ; Sat, 25 May 2019 15:38:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E3FAC2882C; Sat, 25 May 2019 15:38:45 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 90C52286F1 for ; Sat, 25 May 2019 15:38:45 +0000 (UTC) Received: from localhost ([127.0.0.1]:43540 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hUYku-0005ck-RL for patchwork-qemu-devel@patchwork.kernel.org; Sat, 25 May 2019 11:38:44 -0400 Received: from eggs.gnu.org ([209.51.188.92]:35978) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hUYe4-0007m2-St for qemu-devel@nongnu.org; Sat, 25 May 2019 11:31:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hUYNG-0002Mm-Gp for qemu-devel@nongnu.org; Sat, 25 May 2019 11:14:19 -0400 Received: from 2.mo68.mail-out.ovh.net ([46.105.52.162]:44954) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hUYNG-0002Ko-B6 for qemu-devel@nongnu.org; Sat, 25 May 2019 11:14:18 -0400 Received: from player698.ha.ovh.net (unknown [10.109.160.143]) by mo68.mail-out.ovh.net (Postfix) with ESMTP id ED4B612CE66 for ; Sat, 25 May 2019 17:14:16 +0200 (CEST) Received: from kaod.org (lfbn-1-10649-41.w90-89.abo.wanadoo.fr [90.89.235.41]) (Authenticated sender: clg@kaod.org) by player698.ha.ovh.net (Postfix) with ESMTPSA id 77D03625A823; Sat, 25 May 2019 15:14:09 +0000 (UTC) From: =?utf-8?q?C=C3=A9dric_Le_Goater?= To: Peter Maydell Date: Sat, 25 May 2019 17:12:34 +0200 Message-Id: <20190525151241.5017-13-clg@kaod.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190525151241.5017-1-clg@kaod.org> References: <20190525151241.5017-1-clg@kaod.org> MIME-Version: 1.0 X-Ovh-Tracer-Id: 6613536056988568337 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeduuddruddukedgkeejucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecuhedttdenucesvcftvggtihhpihgvnhhtshculddquddttddm X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 46.105.52.162 Subject: [Qemu-devel] [PATCH 12/19] aspeed/timer: Ensure positive muldiv delta 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: Christian Svensson , Andrew Jeffery , qemu-devel@nongnu.org, qemu-arm@nongnu.org, =?utf-8?q?C=C3=A9dric_Le_Goater?= , Joel Stanley Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Christian Svensson If the host decrements the counter register that results in a negative delta. This is then passed to muldiv64 which only handles unsigned numbers resulting in bogus results. This fix ensures the delta being operated on is positive. Test case: kexec a kernel using aspeed_timer and it will freeze on the second bootup when the kernel initializes the timer. With this patch that no longer happens and the timer appears to run OK. Signed-off-by: Christian Svensson Signed-off-by: Cédric Le Goater --- hw/timer/aspeed_timer.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/hw/timer/aspeed_timer.c b/hw/timer/aspeed_timer.c index 9988b8fbbf17..53b70f859c86 100644 --- a/hw/timer/aspeed_timer.c +++ b/hw/timer/aspeed_timer.c @@ -275,7 +275,11 @@ static void aspeed_timer_set_value(AspeedTimerCtrlState *s, int timer, int reg, int64_t delta = (int64_t) value - (int64_t) calculate_ticks(t, now); uint32_t rate = calculate_rate(t); - t->start += muldiv64(delta, NANOSECONDS_PER_SECOND, rate); + if (delta >= 0) { + t->start += muldiv64(delta, NANOSECONDS_PER_SECOND, rate); + } else { + t->start -= muldiv64(-delta, NANOSECONDS_PER_SECOND, rate); + } aspeed_timer_mod(t); } break;