Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031008AbbKEB7N (ORCPT ); Wed, 4 Nov 2015 20:59:13 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:51424 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754887AbbKEB7J (ORCPT ); Wed, 4 Nov 2015 20:59:09 -0500 MIME-Version: 1.0 In-Reply-To: <1445961999-9506-6-git-send-email-fu.wei@linaro.org> References: <1445961999-9506-1-git-send-email-fu.wei@linaro.org> <1445961999-9506-6-git-send-email-fu.wei@linaro.org> Date: Wed, 4 Nov 2015 19:59:07 -0600 Message-ID: Subject: Re: [Linaro-acpi] [PATCH v8 5/5] Watchdog: introduce ARM SBSA watchdog driver From: Timur Tabi To: Fu Wei Cc: Linaro ACPI Mailman List , linux-watchdog@vger.kernel.org, devicetree@vger.kernel.org, lkml , linux-doc@vger.kernel.org, "Rafael J. Wysocki" , Arnd Bergmann , Jonathan Corbet , Jon Masters , Pratyush Anand , Will Deacon , Wim Van Sebroeck , Catalin Marinas , Wei Fu , Rob Herring , Vipul Gandhi , Dave Young , Guenter Roeck Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1214 Lines: 28 On Tue, Oct 27, 2015 at 11:06 AM, wrote: > +static irqreturn_t sbsa_gwdt_interrupt(int irq, void *dev_id) > +{ > + struct sbsa_gwdt *gwdt = (struct sbsa_gwdt *)dev_id; > + struct watchdog_device *wdd = &gwdt->wdd; > + > + /* We don't use pretimeout, trigger WS1 now */ > + if (!wdd->pretimeout) > + sbsa_gwdt_set_wcv(wdd, 0); So I'm still concerned about the fact this driver depends on an interrupt handler in order to properly program the hardware. Unlike some other devices, the SBSA watchdog does not need assistance to reset on a timeout -- it is a "fire and forget" device. What happens if there is a hard lockup, and interrupts no longer work? Keep in mind that 99% of watchdog daemons will not enable the pre-timeout feature because it's new. -- Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/