Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Message-ID: <550d98a41f8c36effb8147201d6c5fdc762994ea.camel@yadro.com>
Subject: Re: [PATCH 3/3] watchdog/aspeed: add support for dual boot
From:   Ivan Mikhaylov <i.mikhaylov@yadro.com>
To:     Guenter Roeck <linux@roeck-us.net>
CC:     Wim Van Sebroeck <wim@linux-watchdog.org>,
        Joel Stanley <joel@jms.id.au>,
        Andrew Jeffery <andrew@aj.id.au>,
        <linux-watchdog@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-aspeed@lists.ozlabs.org>, <linux-kernel@vger.kernel.org>,
        "Alexander Amelkin" <a.amelkin@yadro.com>
Date:   Thu, 22 Aug 2019 17:24:27 +0300
In-Reply-To: <20190822135528.GB8144@roeck-us.net>
References: <1f2cd155057e5ab0cdb20a9a11614bbb09bb49ad.camel@yadro.com>
         <20190821163220.GA11547@roeck-us.net>
         <a022c0590f0fbf22cc8476b5ef3f1c22746429ac.camel@yadro.com>
         <20190822135528.GB8144@roeck-us.net>
Organization: YADRO
Content-Type: text/plain; charset="UTF-8"
User-Agent: Evolution 3.30.5 (3.30.5-1.fc29) 
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Thu, 2019-08-22 at 06:55 -0700, Guenter Roeck wrote:
> On Thu, Aug 22, 2019 at 12:15:20PM +0300, Ivan Mikhaylov wrote:
> > On Wed, 2019-08-21 at 09:32 -0700, Guenter Roeck wrote:
> > > > +	writel(WDT_CLEAR_TIMEOUT_AND_BOOT_CODE_SELECTION,
> > > > +			wdt->base + WDT_CLEAR_TIMEOUT_STATUS);
> > > > +	wdt->wdd.bootstatus |= WDIOF_EXTERN1;
> > > 
> > > The variable reflects the _boot status_. It should not change after
> > > booting.
> > 
> > Okay, then perhaps may we set 'status' handler for watchdog device and
> > check 
> > 'status' file? Right now 'bootstatus' and 'status' are same because there is
> > no
> > handler for 'status'.
> > 
> 
> You would still have to redefine one of the status bits to mean something
> driver specific. You would also still have two different flags to read
> and control cs0 - to read the status, you would read an ioctl (or the
> status sysfs attribute), to write it you would write into access_cs0.
> 
> I guess I must be missing something. What is the problem with using
> access_cs0 for both ?
> 
> Guenter
> 

There is no problem, I'll do that way, thanks!