From patchwork Tue May 30 18:52:26 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juergen Gross X-Patchwork-Id: 9755153 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 24651602F0 for ; Tue, 30 May 2017 18:55:20 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 15B49281E1 for ; Tue, 30 May 2017 18:55:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 09E5E27F10; Tue, 30 May 2017 18:55:20 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 954E327853 for ; Tue, 30 May 2017 18:55:18 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dFmFs-0000NN-Ie; Tue, 30 May 2017 18:52:32 +0000 Received: from mail6.bemta6.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dFmFr-0000NH-7X for xen-devel@lists.xenproject.org; Tue, 30 May 2017 18:52:31 +0000 Received: from [193.109.254.147] by server-2.bemta-6.messagelabs.com id 2B/BC-03058-E6FBD295; Tue, 30 May 2017 18:52:30 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrJLMWRWlGSWpSXmKPExsVyuP0Ov27uft1 Igz8nTCy+b5nM5MDocfjDFZYAxijWzLyk/IoE1oy2lXvZCo5zVkyfuYutgfEDexcjJ4eEgJHE 24n/mLoYuTiEBBYySsxYd44FJMEmoCqx4fopVhBbRMBRYnXbUjCbWcBBYtaso8wgtrBAiMSFr RfBbBag+o3zJgMN4uDgFTCWuLnUG2K+vETHgcksExg5FzAyrGLUKE4tKkst0jU01ksqykzPKM lNzMzRNTQw08tNLS5OTE/NSUwq1kvOz93ECPQWAxDsYPyyLOAQoyQHk5Ior7O1bqQQX1J+SmV GYnFGfFFpTmrxIUYZDg4lCd6gfUA5waLU9NSKtMwcYNjApCU4eJREeJlA0rzFBYm5xZnpEKlT jLocG1av/8IkxJKXn5cqJc57ey9QkQBIUUZpHtwIWAhfYpSVEuZlBDpKiKcgtSg3swRV/hWjO AejkjCvF8gqnsy8ErhNr4COYAI6YtcObZAjShIRUlINjJa8tZdKlI/pVj/15X3+p+nz6VX8H3 LivrtPnrlw5vdLK87cqhCQS1S6sO1fK6N9EvvTQ6fXVZRfMFmgr+t6xDay56JQNzfvfInP+UU ttRtdAnWye9nWPf5WoLJC683R29oM+7dlsaeZBsVpCHVsDWj7b6fo1vg/ic14puGMB1O35Dek zLF/qMRSnJFoqMVcVJwIACtQtbFcAgAA X-Env-Sender: jgross@suse.com X-Msg-Ref: server-15.tower-27.messagelabs.com!1496170349!52338979!1 X-Originating-IP: [195.135.220.15] X-SpamReason: No, hits=0.5 required=7.0 tests=BODY_RANDOM_LONG X-StarScan-Received: X-StarScan-Version: 9.4.19; banners=-,-,- X-VirusChecked: Checked Received: (qmail 38095 invoked from network); 30 May 2017 18:52:29 -0000 Received: from mx2.suse.de (HELO mx1.suse.de) (195.135.220.15) by server-15.tower-27.messagelabs.com with DHE-RSA-CAMELLIA256-SHA encrypted SMTP; 30 May 2017 18:52:29 -0000 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 48DCAAAB4; Tue, 30 May 2017 18:52:29 +0000 (UTC) From: Juergen Gross To: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org Date: Tue, 30 May 2017 20:52:26 +0200 Message-Id: <20170530185226.4666-1-jgross@suse.com> X-Mailer: git-send-email 2.12.3 Cc: Juergen Gross , boris.ostrovsky@oracle.com Subject: [Xen-devel] [PATCH v2] xen: don't print error message in case of missing Xenstore entry X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP When registering for the Xenstore watch of the node control/sysrq the handler will be called at once. Don't issue an error message if the Xenstore node isn't there, as it will be created only when an event is being triggered. Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky --- drivers/xen/manage.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index c1ec8ee80924..60cf71f1b256 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -277,8 +277,16 @@ static void sysrq_handler(struct xenbus_watch *watch, const char *path, err = xenbus_transaction_start(&xbt); if (err) return; - if (xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key) < 0) { - pr_err("Unable to read sysrq code in control/sysrq\n"); + err = xenbus_scanf(xbt, "control", "sysrq", "%c", &sysrq_key); + if (err < 0) { + /* + * The Xenstore watch fires directly after registering it and + * after a suspend/resume cycle. So ENOENT is no error but + * might happen in those cases. + */ + if (err != -ENOENT) + pr_err("Error %d reading sysrq code in control/sysrq\n", + err); xenbus_transaction_end(xbt, 1); return; }