From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH v3 5/6] Watchdog: introduce ARM SBSA watchdog driver Date: Fri, 29 May 2015 07:54:18 -0700 Message-ID: <55687D9A.8080409@roeck-us.net> References: <=fu.wei@linaro.org> <1432548193-19569-1-git-send-email-fu.wei@linaro.org> <1432548193-19569-6-git-send-email-fu.wei@linaro.org> <55637A6D.3080403@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-doc-owner@vger.kernel.org To: Fu Wei Cc: Suravee Suthikulpanit , Linaro ACPI Mailman List , linux-watchdog@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Wei Fu , G Gregory , Al Stone , Hanjun Guo , Timur Tabi , Ashwin Chaugule , Arnd Bergmann , vgandhi@codeaurora.org, wim@iguana.be, Jon Masters , Leo Duran , Jon Corbet , Mark Rutland , Catalin Marinas , Will Deacon List-Id: devicetree@vger.kernel.org On 05/29/2015 02:11 AM, Fu Wei wrote: [ ... ] >>> + >>> + status = sbsa_gwdt_cf_read(SBSA_GWDT_WCS, wdd); >>> + if (status & SBSA_GWDT_WCS_WS1) { >>> + dev_warn(dev, "System reset by WDT(WCS: %x, WCV: %llx)\n", >>> + status, sbsa_gwdt_get_wcv(wdd)); >> >> >> Does this message (specifically the WCS / WCV values) have any >> useful meaning for the user ? > > I think so, according to SBSA spec: > If WS0 is asserted and a timeout refresh occurs then the following must occur: > If the system is compliant to SBSA level 2 or higher the compare > value must retain its current value. This means that the compare value > records the time that WS1 is asserted. > > So, I think WCV can log the time when system reset by WDT, that may > help user figure out the problem. but WCS can be delete I think. > How would that help ? It is just a number with no reference to anything. Thanks, Guenter