From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5766CC54FB9 for ; Wed, 15 Nov 2023 19:50:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235406AbjKOTux (ORCPT ); Wed, 15 Nov 2023 14:50:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235413AbjKOTuw (ORCPT ); Wed, 15 Nov 2023 14:50:52 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4DB4B1B8 for ; Wed, 15 Nov 2023 11:50:49 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C142DC433C9; Wed, 15 Nov 2023 19:50:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700077848; bh=kkUhoKOPjqVrw3JURDbyklWE42AI7aXk+h3qZOEmAXg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uV1ba0YYMzhDEoMS/2VslbsgcjHZyNjGXhMtSQKCMdSw543gdc4FF4p4cPm/JQYem XIzaGxxA2KmKas4OVpyq/Ca9idsWCjjVTSPfT8KK7qAn6lHapVsjdDfsbwn19iptF3 KY2jHX/E9FquoC7kG35Yshfh9tCz3bEzG/9VZsUw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Linus Walleij , Guenter Roeck , Wim Van Sebroeck , Sasha Levin Subject: [PATCH 6.6 540/603] watchdog: ixp4xx: Make sure restart always works Date: Wed, 15 Nov 2023 14:18:05 -0500 Message-ID: <20231115191649.183935257@linuxfoundation.org> X-Mailer: git-send-email 2.42.1 In-Reply-To: <20231115191613.097702445@linuxfoundation.org> References: <20231115191613.097702445@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Linus Walleij [ Upstream commit b4075ecfe348a44209534c75ad72392c63a489a6 ] The IXP4xx watchdog in early "A0" silicon is unreliable and cannot be registered, however for some systems such as the USRobotics USR8200 the watchdog is the only restart option, so implement a "dummy" watchdog that can only support restart in this case. Fixes: 1aea522809e6 ("watchdog: ixp4xx: Implement restart") Signed-off-by: Linus Walleij Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20230926-ixp4xx-wdt-restart-v2-1-15cf4639b423@linaro.org Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck Signed-off-by: Sasha Levin --- drivers/watchdog/ixp4xx_wdt.c | 28 +++++++++++++++++++++++++--- 1 file changed, 25 insertions(+), 3 deletions(-) diff --git a/drivers/watchdog/ixp4xx_wdt.c b/drivers/watchdog/ixp4xx_wdt.c index 607ce4b8df574..ec0c08652ec2f 100644 --- a/drivers/watchdog/ixp4xx_wdt.c +++ b/drivers/watchdog/ixp4xx_wdt.c @@ -105,6 +105,25 @@ static const struct watchdog_ops ixp4xx_wdt_ops = { .owner = THIS_MODULE, }; +/* + * The A0 version of the IXP422 had a bug in the watchdog making + * is useless, but we still need to use it to restart the system + * as it is the only way, so in this special case we register a + * "dummy" watchdog that doesn't really work, but will support + * the restart operation. + */ +static int ixp4xx_wdt_dummy(struct watchdog_device *wdd) +{ + return 0; +} + +static const struct watchdog_ops ixp4xx_wdt_restart_only_ops = { + .start = ixp4xx_wdt_dummy, + .stop = ixp4xx_wdt_dummy, + .restart = ixp4xx_wdt_restart, + .owner = THIS_MODULE, +}; + static const struct watchdog_info ixp4xx_wdt_info = { .options = WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE @@ -114,14 +133,17 @@ static const struct watchdog_info ixp4xx_wdt_info = { static int ixp4xx_wdt_probe(struct platform_device *pdev) { + static const struct watchdog_ops *iwdt_ops; struct device *dev = &pdev->dev; struct ixp4xx_wdt *iwdt; struct clk *clk; int ret; if (!(read_cpuid_id() & 0xf) && !cpu_is_ixp46x()) { - dev_err(dev, "Rev. A0 IXP42x CPU detected - watchdog disabled\n"); - return -ENODEV; + dev_info(dev, "Rev. A0 IXP42x CPU detected - only restart supported\n"); + iwdt_ops = &ixp4xx_wdt_restart_only_ops; + } else { + iwdt_ops = &ixp4xx_wdt_ops; } iwdt = devm_kzalloc(dev, sizeof(*iwdt), GFP_KERNEL); @@ -141,7 +163,7 @@ static int ixp4xx_wdt_probe(struct platform_device *pdev) iwdt->rate = IXP4XX_TIMER_FREQ; iwdt->wdd.info = &ixp4xx_wdt_info; - iwdt->wdd.ops = &ixp4xx_wdt_ops; + iwdt->wdd.ops = iwdt_ops; iwdt->wdd.min_timeout = 1; iwdt->wdd.max_timeout = U32_MAX / iwdt->rate; iwdt->wdd.parent = dev; -- 2.42.0