From patchwork Mon Sep 13 11:41:43 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kiszka X-Patchwork-Id: 12488599 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=-20.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 407A4C433F5 for ; Mon, 13 Sep 2021 11:42:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A26F61056 for ; Mon, 13 Sep 2021 11:42:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237978AbhIMLnT (ORCPT ); Mon, 13 Sep 2021 07:43:19 -0400 Received: from gecko.sbs.de ([194.138.37.40]:49200 "EHLO gecko.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236395AbhIMLnS (ORCPT ); Mon, 13 Sep 2021 07:43:18 -0400 Received: from mail2.sbs.de (mail2.sbs.de [192.129.41.66]) by gecko.sbs.de (8.15.2/8.15.2) with ESMTPS id 18DBfiqp009507 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 13 Sep 2021 13:41:44 +0200 Received: from [167.87.36.252] ([167.87.36.252]) by mail2.sbs.de (8.15.2/8.15.2) with ESMTP id 18DBfhOV005983; Mon, 13 Sep 2021 13:41:43 +0200 From: Jan Kiszka Subject: [RFC][PATCH] watchdog: rti-wdt: Provide set_timeout handler to make existing userspace happy To: Wim Van Sebroeck , Guenter Roeck Cc: linux-watchdog@vger.kernel.org, Linux Kernel Mailing List , Tero Kristo , "Su, Bao Cheng (RC-CN DF FA R&D)" Message-ID: <4d82b8ce-bc34-e4b2-c5fe-9e883b0db59d@siemens.com> Date: Mon, 13 Sep 2021 13:41:43 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org From: Jan Kiszka Prominent userspace - systemd - cannot handle watchdogs without WDIOF_SETTIMEOUT, even if it was configured to the same time as the driver selected or was used by firmware to start the watchdog. To avoid failing in this case, implement a handler that only fails if a deviating set_timeout is requested. Signed-off-by: Jan Kiszka --- See also https://github.com/systemd/systemd/issues/20683 drivers/watchdog/rti_wdt.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c index 359302f71f7e..365255b15a0d 100644 --- a/drivers/watchdog/rti_wdt.c +++ b/drivers/watchdog/rti_wdt.c @@ -173,13 +173,27 @@ static unsigned int rti_wdt_get_timeleft_ms(struct watchdog_device *wdd) return timer_counter; } +static int rti_wdt_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + /* + * Updating the timeout after start is actually not supported, but + * let's ignore requests for the already configured value. Helps + * existing userspace such as systemd. + */ + if (timeout != heartbeat) + return -EOPNOTSUPP; + + return 0; +} + static unsigned int rti_wdt_get_timeleft(struct watchdog_device *wdd) { return rti_wdt_get_timeleft_ms(wdd) / 1000; } static const struct watchdog_info rti_wdt_info = { - .options = WDIOF_KEEPALIVEPING, + .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT, .identity = "K3 RTI Watchdog", }; @@ -187,6 +201,7 @@ static const struct watchdog_ops rti_wdt_ops = { .owner = THIS_MODULE, .start = rti_wdt_start, .ping = rti_wdt_ping, + .set_timeout = rti_wdt_set_timeout, .get_timeleft = rti_wdt_get_timeleft, };