From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Message-ID: <1489163292.20145.194.camel@linux.intel.com> Subject: Re: [PATCH v1] watchdog: intel-mid_wdt: Keep watchdog running From: Andy Shevchenko To: Guenter Roeck Cc: Wim Van Sebroeck , linux-watchdog@vger.kernel.org Date: Fri, 10 Mar 2017 18:28:12 +0200 In-Reply-To: <20170308191652.GB4486@roeck-us.net> References: <20170308111029.60744-1-andriy.shevchenko@linux.intel.com> <846f18ec-e41c-364e-c867-fa6b3dbc18d4@roeck-us.net> <1488985870.20145.137.camel@linux.intel.com> <20170308191652.GB4486@roeck-us.net> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 8bit List-ID: On Wed, 2017-03-08 at 11:16 -0800, Guenter Roeck wrote: > On Wed, Mar 08, 2017 at 05:11:10PM +0200, Andy Shevchenko wrote: > > On Wed, 2017-03-08 at 06:21 -0800, Guenter Roeck wrote: > > > On 03/08/2017 03:10 AM, Andy Shevchenko wrote: > > > > Firmware followed by bootloader leaves watchdog running. > > > Is that always the case ? > > > > Yes if no-one patched boot loader specifically to avoid this. > > > > >  If not, does it hurt if the watchdog is pinged > > > while not active ? > > > > > > Also, this assumes that its default timeout is in the default > > > range > > > configured by the driver, ie not (much) lower than 30 seconds. > > > > Correct. It is hard coded in SCU firmware (60 seconds IIRC). U-Boot > > for > > now doesn't change it. > > > > > Not objecting, but it would help to have comments in the code > > > explaining > > > the context in some more detail. > > > > Last time you were not satisfied by the line which stops the running > > watchdog [1]. I found a way how to keep it running gracefully, which > > I > > proposed to do at that time (assuming boot loader doesn't stop it) > > [2]. > > > > I'm confused now what is preferable way to do the things? > > > > The suggested patch is ok. I was just asking for additional comments, > along the line of 1) the SCU firmware sets the timeout to 60s, the > default > timeout of 30s is therefore safe, and 2) that the watchdog is by > default > enabled in the SCU firmware (and, if appropriate, that it doesn't get > a > hiccup if it is pinged if it should have been disabled for some > unspecified > / unknown reason). Okay, I will send v2 with additional comments. Thanks for clarifying! P.S. It looks like we have to add some lines in the driver for U-Boot to make developer pay attention to the potential asynchronization. -- Andy Shevchenko Intel Finland Oy