From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932516AbbEWU1G (ORCPT ); Sat, 23 May 2015 16:27:06 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:37187 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932432AbbEWU1E (ORCPT ); Sat, 23 May 2015 16:27:04 -0400 Message-ID: <5560E294.6040903@codeaurora.org> Date: Sat, 23 May 2015 15:27:00 -0500 From: Timur Tabi User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:36.0) Gecko/20100101 Firefox/36.0 SeaMonkey/2.33.1 MIME-Version: 1.0 To: Guenter Roeck , 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 , Ashwin Chaugule , Arnd Bergmann , vgandhi@codeaurora.org, wim@iguana.be, Jon Masters , Leo Duran , Jon Corbet , Mark Rutland Subject: Re: [PATCH v2 6/7] Watchdog: introduce ARM SBSA watchdog driver References: <=fu.wei@linaro.org> <1432197156-16947-1-git-send-email-fu.wei@linaro.org> <1432197156-16947-7-git-send-email-fu.wei@linaro.org> <555DFCD4.3040701@codeaurora.org> <5560D7AC.50009@codeaurora.org> <5560DCB6.3090008@roeck-us.net> In-Reply-To: <5560DCB6.3090008@roeck-us.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Guenter Roeck wrote: > > However, the pretimeout concept assumes that there are two timers > which can be set independently. As you had pointed out earlier, > and as the specification seems to confirm, that is not the case here. > As such, I don't really understand why and how the pretimeout / timeout > concept would add any value here and not just make things more > complicated than necessary. Maybe I am just missing something. It might be possible to load a new value into the WOR register after the WS0 interrupt occurs. That is, in the interrupt handler, we can do something like this: if (status & SBSA_GWDT_WCS_WS0) // write new WOR value, // then ping watchdog so that it's loaded I'm not convinced that it's worth it, however. It would require interrupts to still be working when WS0 times out, which somewhat defeats the purpose of a watchdog. -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Timur Tabi Subject: Re: [PATCH v2 6/7] Watchdog: introduce ARM SBSA watchdog driver Date: Sat, 23 May 2015 15:27:00 -0500 Message-ID: <5560E294.6040903@codeaurora.org> References: <=fu.wei@linaro.org> <1432197156-16947-1-git-send-email-fu.wei@linaro.org> <1432197156-16947-7-git-send-email-fu.wei@linaro.org> <555DFCD4.3040701@codeaurora.org> <5560D7AC.50009@codeaurora.org> <5560DCB6.3090008@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: <5560DCB6.3090008-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Sender: linux-watchdog-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Guenter Roeck , Fu Wei Cc: Suravee Suthikulpanit , Linaro ACPI Mailman List , linux-watchdog-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Wei Fu , G Gregory , Al Stone , Hanjun Guo , Ashwin Chaugule , Arnd Bergmann , vgandhi-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, wim-IQzOog9fTRqzQB+pC5nmwQ@public.gmane.org, Jon Masters , Leo Duran , Jon Corbet , Mark Rutland List-Id: devicetree@vger.kernel.org Guenter Roeck wrote: > > However, the pretimeout concept assumes that there are two timers > which can be set independently. As you had pointed out earlier, > and as the specification seems to confirm, that is not the case here. > As such, I don't really understand why and how the pretimeout / timeout > concept would add any value here and not just make things more > complicated than necessary. Maybe I am just missing something. It might be possible to load a new value into the WOR register after the WS0 interrupt occurs. That is, in the interrupt handler, we can do something like this: if (status & SBSA_GWDT_WCS_WS0) // write new WOR value, // then ping watchdog so that it's loaded I'm not convinced that it's worth it, however. It would require interrupts to still be working when WS0 times out, which somewhat defeats the purpose of a watchdog. -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation. -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html