From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965845AbbKEODl (ORCPT ); Thu, 5 Nov 2015 09:03:41 -0500 Received: from mail-oi0-f50.google.com ([209.85.218.50]:35909 "EHLO mail-oi0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965213AbbKEODi (ORCPT ); Thu, 5 Nov 2015 09:03:38 -0500 MIME-Version: 1.0 In-Reply-To: <563B5DF9.6080102@codeaurora.org> References: <1445961999-9506-1-git-send-email-fu.wei@linaro.org> <1445961999-9506-6-git-send-email-fu.wei@linaro.org> <563AE588.1080009@roeck-us.net> <563B5DF9.6080102@codeaurora.org> Date: Thu, 5 Nov 2015 22:03:37 +0800 Message-ID: Subject: Re: [Linaro-acpi] [PATCH v8 5/5] Watchdog: introduce ARM SBSA watchdog driver From: Fu Wei To: Timur Tabi Cc: Guenter Roeck , 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 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Timur On 5 November 2015 at 21:47, Timur Tabi wrote: > Guenter Roeck wrote: >> >> I would feel much more comfortable if the driver would just use the >> standard >> watchdog timeout and live with (worst case) 20 seconds timeout for now. > > > Actually, I'm wondering where the 20 seconds comes from. When I load my > driver on our hardware, it calculates a maximum timeout of 214 seconds, and > that's just to WS0. SBSA 2.3 Page 23 : Note: the watchdog offset register is 32 bits wide. This gives a maximum watch period of around 10s at a system counter frequency of 400MHz. If a larger watch period is required then the compare value can be programmed directly into the compare value register. 214s means your system counter is approximately at 20MHz which is in the range of (10MHz ~ 400MHz) SBSA 2.3 Page 13 : The System Counter (of the Generic Timer) shall run at a minimum frequency of 10MHz and maximum of 400MHz. > > -- > 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. -- Best regards, Fu Wei Software Engineer Red Hat Software (Beijing) Co.,Ltd.Shanghai Branch Ph: +86 21 61221326(direct) Ph: +86 186 2020 4684 (mobile) Room 1512, Regus One Corporate Avenue,Level 15, One Corporate Avenue,222 Hubin Road,Huangpu District, Shanghai,China 200021 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fu Wei Subject: Re: [Linaro-acpi] [PATCH v8 5/5] Watchdog: introduce ARM SBSA watchdog driver Date: Thu, 5 Nov 2015 22:03:37 +0800 Message-ID: References: <1445961999-9506-1-git-send-email-fu.wei@linaro.org> <1445961999-9506-6-git-send-email-fu.wei@linaro.org> <563AE588.1080009@roeck-us.net> <563B5DF9.6080102@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <563B5DF9.6080102-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org> Sender: linux-watchdog-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Timur Tabi Cc: Guenter Roeck , Linaro ACPI Mailman List , linux-watchdog-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, lkml , linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.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 List-Id: devicetree@vger.kernel.org Hi Timur On 5 November 2015 at 21:47, Timur Tabi wrote: > Guenter Roeck wrote: >> >> I would feel much more comfortable if the driver would just use the >> standard >> watchdog timeout and live with (worst case) 20 seconds timeout for now. > > > Actually, I'm wondering where the 20 seconds comes from. When I load my > driver on our hardware, it calculates a maximum timeout of 214 seconds, and > that's just to WS0. SBSA 2.3 Page 23 : Note: the watchdog offset register is 32 bits wide. This gives a maximum watch period of around 10s at a system counter frequency of 400MHz. If a larger watch period is required then the compare value can be programmed directly into the compare value register. 214s means your system counter is approximately at 20MHz which is in the range of (10MHz ~ 400MHz) SBSA 2.3 Page 13 : The System Counter (of the Generic Timer) shall run at a minimum frequency of 10MHz and maximum of 400MHz. > > -- > 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. -- Best regards, Fu Wei Software Engineer Red Hat Software (Beijing) Co.,Ltd.Shanghai Branch Ph: +86 21 61221326(direct) Ph: +86 186 2020 4684 (mobile) Room 1512, Regus One Corporate Avenue,Level 15, One Corporate Avenue,222 Hubin Road,Huangpu District, Shanghai,China 200021 -- 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