From patchwork Tue Oct 30 09:31:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kurt Kanzenbach X-Patchwork-Id: 10661223 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 027273CF1 for ; Tue, 30 Oct 2018 16:09:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E19BF2A834 for ; Tue, 30 Oct 2018 16:09:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D5E502A83C; Tue, 30 Oct 2018 16:09:11 +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=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 8D8712A834 for ; Tue, 30 Oct 2018 16:09:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=d1AzWv9sQhvpmhmEJlhxLL0+lNqmobAIfccy0KR2mG0=; b=pGK+boYvgkdzR+ZNhd3T5QSnkb X3fEbFSJmNXUItEIzzZByYVySYR4NBWEjghcx6Viyep6INhxI3SqRUEm1+RkAKHZmoggMjX1pJtBW 4fnNNHjPGab1vGeQ5uxG9xUZ8lsj4gu5iPOLnZ66jKIrsssZEZyq6NoGSEE4TSNoFFqQequ3+Y+Sv mmeqkYtWaX14Z0rO6rR/NrrwWebEY6w51RTAPqFqfAwZXqN5q7N6NA1rhIQj8o/7n79XeqZw83VBl EeELErhfULx27+mEGy4XfsJQPDAezg6UXqXLl6d4J1pEgErQPgd+AjrngF8/cQUtRW4GabJkd3q4j PvAa09VA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gHWZp-0008P6-Su; Tue, 30 Oct 2018 16:09:09 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gHVsC-0002Rf-5i for linux-arm-kernel@bombadil.infradead.org; Tue, 30 Oct 2018 15:24:04 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=References:In-Reply-To:Message-Id:Date: Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=K8VQVdK5zUxbqOB4FoFiKGz7Kct7JLFS1TqE0+kXXsw=; b=L7JIN35M2MyZiwoIaNmlYl7V9 L4Llsxtj2htgekz5OHOpbYia+AYEpS4ccarj5Vrceuome13v8Hqnqy7LiDZKbJKWv4Nky1m9D409B ffIEgpBPmMHksWoYkwx2REktC+lMAfyctbXxZzGlAzeUN8uKUJlsF9cNoJLMWg3iRd3NIYLz1s1Mo QgxeCK11pMYbvMBpR7ZqEQynWTA3CIBcd/tydXoP3tj99AkFA5PU81H5SThqYxyW9VKK6IG+D4Kw8 Zyn9VSh8tnuopsHpSAAzdg5puZbHagIKz7HirGYFZXgUIC34T+2GPhG5iIiI8I/95lTpe0/+3I8LZ QQl8E83Xw==; Received: from galois.linutronix.de ([2a01:7a0:2:106d:700::1]) by casper.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gHQP8-0005bV-WC for linux-arm-kernel@lists.infradead.org; Tue, 30 Oct 2018 09:33:44 +0000 Received: from hsi-kbw-5-158-153-52.hsi19.kabel-badenwuerttemberg.de ([5.158.153.52] helo=kurt.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.80) (envelope-from ) id 1gHQNB-0003Lk-Dn; Tue, 30 Oct 2018 10:31:41 +0100 From: Kurt Kanzenbach To: Anirudha Sarangi , John Linn , "David S. Miller" Subject: [PATCH 1/2] net: axienet: recheck condition after timeout in mdio_wait() Date: Tue, 30 Oct 2018 10:31:38 +0100 Message-Id: <20181030093139.10226-2-kurt@linutronix.de> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20181030093139.10226-1-kurt@linutronix.de> References: <20181030093139.10226-1-kurt@linutronix.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181030_093343_047081_262C9407 X-CRM114-Status: GOOD ( 12.02 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andrew Lunn , Kurt Kanzenbach , netdev@vger.kernel.org, Radhey Shyam Pandey , YueHaibing , Michal Simek , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The function could report a false positive if it gets preempted between reading the XAE_MDIO_MCR_OFFSET register and checking for the timeout. In such a case, the condition has to be rechecked to avoid false positives. Therefore, check for expected condition even after the timeout occurred. Signed-off-by: Kurt Kanzenbach --- drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c b/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c index 757a3b37ae8a..4f13125e4942 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c @@ -21,15 +21,26 @@ int axienet_mdio_wait_until_ready(struct axienet_local *lp) { unsigned long end = jiffies + 2; - while (!(axienet_ior(lp, XAE_MDIO_MCR_OFFSET) & - XAE_MDIO_MCR_READY_MASK)) { + u32 val; + + while (1) { + val = axienet_ior(lp, XAE_MDIO_MCR_OFFSET); + + if (val & XAE_MDIO_MCR_READY_MASK) + return 0; + if (time_before_eq(end, jiffies)) { - WARN_ON(1); - return -ETIMEDOUT; + val = axienet_ior(lp, XAE_MDIO_MCR_OFFSET); + break; } + udelay(1); } - return 0; + if (val & XAE_MDIO_MCR_READY_MASK) + return 0; + + WARN_ON(1); + return -ETIMEDOUT; } /**