From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Subject: Re: [PATCH v3] watchdog: Add watchdog timer support for the WinSystems EBC-C384 To: Guenter Roeck , One Thousand Gnomes References: <20160125190942.GA6824@sophia> <20160125192810.2487661b@lxorguk.ukuu.org.uk> <56A6889E.60208@roeck-us.net> Cc: wim@iguana.be, linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org From: William Breathitt Gray Message-ID: <56A6B198.2080205@gmail.com> Date: Mon, 25 Jan 2016 18:36:56 -0500 MIME-Version: 1.0 In-Reply-To: <56A6889E.60208@roeck-us.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit List-ID: On 01/25/2016 03:42 PM, Guenter Roeck wrote: > On 01/25/2016 11:28 AM, One Thousand Gnomes wrote: >> If ask for 299 seconds surely I should get 300 not 240 ? >> (Whether to round off or round up is an interesting question for the >> middle range - does it go off early or late - I'd have said late but...) >> > > Matter of endless discussion. Some argue that the value should be rounded > up, some argue that it should be rounded down, some argue that it should > be rounded to the closest match. Each camp has its own valid arguments. > I usually leave it up to the driver's author to decide, with a slight > preference to never select a value larger than requested. I implemented it to round down simply because it was the simplest solution (i.e. integer truncation). Although I see merit in an implementation that rounds to the closest valid value, I'll keep the current implementation for now due to its simplicity; if enough users of the driver prefer a different implementation, then I'll add it in a later patch. >> Is there no ACPI entry for it ? >> > Same here. As long as the board is identified, I tend to leave it up > to the driver author to decide _how_ to identify it. > > Only question for me would be if the watchdog timer is implemented > in a Super-IO chip, and if so, if it would be possible to use the chip > identification instead of a DMI (or ACPI) entry to instantiate the driver. I do not believe there is an ACPI entry for it. Interestingly, the watchdog timer BIOS configuration option for this motherboard is listed under the Super I/O menu; perhaps this watchdog timer is implemented in the Super I/O chip. The manual for this motherboard does not provide much information about the Super I/O chip (no model number, etc.), and neither sensors-detect nor superiotool was able to detect it. I've sent an email to the motherboard company (WinSystems) requesting further information about the Super I/O chip and whether the watchdog timer is built-in to the Super I/O chip. William Breathitt Gray