From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH v10 5/5] Watchdog: ARM SBSA Generic Watchdog half timeout panic support Date: Fri, 5 Feb 2016 06:42:42 -0800 Message-ID: <56B4B4E2.40105@roeck-us.net> References: <1454519923-25230-1-git-send-email-fu.wei@linaro.org> <1454519923-25230-6-git-send-email-fu.wei@linaro.org> <56B23883.7000501@codeaurora.org> <56B23E99.1030604@codeaurora.org> <56B2423B.1020109@codeaurora.org> <56B24642.8090105@codeaurora.org> <56B24AB5.3070001@codeaurora.org> <56B2DEE4.7060901@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: Timur Tabi , Rob Herring , =?UTF-8?Q?Pawe=c5=82_Moll?= , Mark Rutland , Ian Campbell , Kumar Gala , Wim Van Sebroeck , Jon Corbet , Catalin Marinas , Will Deacon , Suravee Suthikulpanit , LKML , linux-watchdog@vger.kernel.org, linux-doc@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Linaro ACPI Mailman List , rruigrok@codeaurora.org, "Abdulhamid, Harb" , Christopher Covington , Dave Young , Pratyush Anand , G Gregory , Al List-Id: devicetree@vger.kernel.org On 02/05/2016 01:51 AM, Fu Wei wrote: > Hi Guenter, > > On 4 February 2016 at 13:17, Guenter Roeck wrote: >> On 02/03/2016 03:00 PM, Fu Wei wrote: >>> >>> On 4 February 2016 at 02:45, Timur Tabi wrote: >>>> >>>> Fu Wei wrote: >>>>> >>>>> >>>>> As you know I have made the pre-timeout support patch, If people like >>>>> it, i am happy to go on upstream it separately. >>>>> >>>>> If we want to use pre-timeout here, user only can use get_pretimeout >>>>> and disable panic by setting pretimeout to 0 >>>>> but user can not really set pretimeout, because "pre-timeout == >>>>> timeout / 2 (always)". >>>>> if user want to change pretimeout, he/she has to set_time instead. >>>> >>>> >>>> >>>> Ok, I think patches 4 and 5 should be combined, and I think the Kconfig >>>> entry should be removed and just use panic_enabled. >> >> >> Agreed. > > np, will do > >>> >>> >>> NP, will update this patchset like that , thanks :-) >>> >> >> Also, if panic is enabled, the timeout needs to be adjusted accordingly >> (to only panic after the entire timeout period has expired, not after >> half of it). We can not panic the system after timeout / 2. > > OK, my thought is > > if panic is enabled : > |--------WOR-------WS0--------WOR-------WS1 > |------timeout------(panic)------timeout-----reset > > if panic is disabled . > |--------WOR-------WS0--------WOR-------WS1 > |---------------------timeout---------------------reset > > panic_enabled only can be configured when module is loaded by module parameter > > But user should know that max_timeout(panic_enable) = > max_timeout(panic_disable) / 2 > That means you'll have to update max_timeout accordingly. >> >> I am not too happy with the parameter name (panic_enabled). How about >> "action", to match machzwd ? > > yes, makes sense. Maybe we can do something like this: > > /* > * action refers to action taken when watchdog gets WS0 > * 0 = SKIP > * 1 = PANIC > * defaults to SKIP (0) > */ > static int action; > module_param(action, int, 0); > MODULE_PARM_DESC(action, "after watchdog gets WS0 interrupt, do: " > "0 = SKIP(*) 1 = PANIC"); > Yes, though I would suggest to use lower case letters. Thanks, Guenter