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From: Tom Rini <trini@konsulko.com>
To: u-boot@lists.denx.de
Subject: [PATCH 2/2] watchdog: add watchdog behavior configuration
Date: Mon, 28 Sep 2020 11:34:10 -0400	[thread overview]
Message-ID: <20200928153410.GB14816@bill-the-cat> (raw)
In-Reply-To: <f55d5d2558e3dcd918dbac4831a9efff@walle.cc>

On Sun, Sep 27, 2020 at 06:06:38PM +0200, Michael Walle wrote:
> Am 2020-09-26 14:44, schrieb Tom Rini:
> [..]
> > > If we want to have a hardware based watchdog in the UEFI context, we
> > > need a U-Boot internal API by which we can enable and disable a
> > > hardware
> > > watchdog with an arbitrary duration (>> 5 min) with 1 second
> > > resolution.
> > > Then our implementation of SetWatchdogTimer() could call into this
> > > API.
> > 
> > Thanks for excerpting from the UEFI spec where it talks about a
> > "watchdog" at all.  It's clear from these excerpts that the spec simply
> > does not talk about a hardware watchdog at all and is using the term in
> > one of its other meanings.  Which means that we need to figure out and
> > document something nominally sane so at least it's not a surprise to the
> > user.
> > 
> > Michael, what driver under drivers/watchdog/ is your platform using
> > exactly?  Thanks!
> 
> In its current form (i.e. basic BSP support) it uses the sp805_wdt.c;
> which is a nice to have, but the real watchdog is an external device.
> There is no support in U-Boot for it yet, but I'm planning to add it
> and thus I need the CONFIG_WDT ;)
> 
> Currently this external watchdog is disabled (there are non-volatile
> configuration bits on the board and one bit is for disabling this
> watchdog at startup). Otherwise it would always activate the board's
> failsafe mode because it isn't triggered by U-Boot.
> 
> And yes, this watchdog also have a lock bit, once set, you cannot
> deactivate it anymore (although you can change the timeout period
> in a given range).
> 
> Because at the moment there is no driver for this watchdog yet (it
> is a custom one), my newest version of my "basic board support for
> Kontron sl28" has the CONFIG_WDT deactivated. I prefer having a
> usable bootefi to have support for the SoC internal watchdog.

Thanks for explaining.  I was asking in part because I was wondering if
that SoC was falling into the case of drivers/watchdog/imx_watchdog.c

-- 
Tom
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  reply	other threads:[~2020-09-28 15:34 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-23 16:45 [PATCH 1/2] watchdog: Hide WATCHDOG_RESET_DISABLE Michael Walle
2020-09-23 16:45 ` [PATCH 2/2] watchdog: add watchdog behavior configuration Michael Walle
2020-09-23 17:01   ` Mark Kettenis
2020-09-23 17:14     ` Tom Rini
2020-09-23 17:31       ` Heinrich Schuchardt
2020-09-23 17:35         ` Tom Rini
2020-09-24  7:33           ` Michael Walle
2020-09-24  8:10             ` Mark Kettenis
2020-09-24  8:20               ` Michael Walle
2020-09-24 10:22                 ` Mark Kettenis
2020-09-24 21:05                   ` Michael Walle
2020-09-24 13:19             ` Tom Rini
2020-09-24 20:30               ` Michael Walle
2020-09-24 20:58                 ` Mark Kettenis
2020-09-24 21:14                   ` Michael Walle
2020-09-25  1:17                     ` Tom Rini
2020-09-25  8:36               ` Wolfgang Denk
2020-09-25 11:29                 ` Heinrich Schuchardt
2020-09-25 13:00                   ` Tom Rini
2020-09-25 13:26                     ` Heinrich Schuchardt
2020-09-26  8:45                       ` Wolfgang Denk
2020-09-26 10:54                         ` Mark Kettenis
2020-09-26 12:39                           ` Heinrich Schuchardt
2020-09-26 12:44                             ` Tom Rini
2020-09-27 16:06                               ` Michael Walle
2020-09-28 15:34                                 ` Tom Rini [this message]
2020-09-26 14:40                             ` Wolfgang Denk
2020-09-26 14:22                           ` Wolfgang Denk
2020-09-25 13:04                   ` Wolfgang Denk
2020-10-04 14:55                     ` Michael Walle
2020-10-04 15:10                       ` Heinrich Schuchardt
2020-10-04 15:40                         ` Tom Rini
2020-09-23 17:53       ` Mark Kettenis
2020-09-23 18:51         ` Heinrich Schuchardt
2020-09-23 19:02           ` Tom Rini
2020-09-23 20:01             ` Heinrich Schuchardt
2020-09-23 20:23               ` Tom Rini
2020-09-23 20:58                 ` Heinrich Schuchardt
2020-09-23 21:09                   ` Tom Rini
2020-09-23 20:38           ` Michael Walle
2020-09-23 21:01             ` Heinrich Schuchardt
2020-09-23 17:21   ` Heinrich Schuchardt
2020-09-23 17:28     ` Tom Rini
2020-09-24  6:53       ` Michael Walle

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