Re: Fwd: [PATCH 4/8] watchdog: davinci: add GET_STATUS option support

[ivan.khoronzhuk]

On 11/18/2013 06:24 PM, Guenter Roeck wrote:
> On Mon, Nov 18, 2013 at 04:21:06PM +0200, ivan.khoronzhuk wrote:
> > On 11/17/2013 04:24 AM, Guenter Roeck wrote:
> > > On 11/06/2013 03:32 AM, ivan.khoronzhuk wrote:
> > > > When watchdog timer is expired we can know about it thought
> > >
> > > thought -> through or with
> >
> > Ok
> >
> > > > GET_STATUS ioctl option.
> > > >
> > > > Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxx>
> > > > ---
> > > >    drivers/watchdog/davinci_wdt.c |   13 +++++++++++++
> > > >    1 file changed, 13 insertions(+)
> > > >
> > > > diff --git a/drivers/watchdog/davinci_wdt.c
> > > > b/drivers/watchdog/davinci_wdt.c
> > > > index 6cbf2e1..a371b2d 100644
> > > > --- a/drivers/watchdog/davinci_wdt.c
> > > > +++ b/drivers/watchdog/davinci_wdt.c
> > > > @@ -144,6 +144,18 @@ static unsigned int
> > > > davinci_wdt_get_timeleft(struct watchdog_device *wdd)
> > > >        return wdd->timeout - timer_counter;
> > > >    }
> > > >
> > > > +static unsigned int davinci_wdt_status(struct watchdog_device *wdd)
> > > > +{
> > > > +    u32 val;
> > > > +    struct davinci_wdt_device *davinci_wdt = watchdog_get_drvdata(wdd);
> > > > +
> > > > +    val = ioread32(davinci_wdt->base + WDTCR);
> > > > +    if (val & WDFLAG)
> > > > +        return WDIOF_CARDRESET;
> > > > +
> > >       "Card previously reset the CPU"
> > >
> > > Is this really accurate / correct ?
> > >
> > > My understanding is that the status is supposed to return the reason for
> > > a previous reset/reboot,
> > > not the curent condition.
> >
> > Actually it is not so good correlate with the purpose, but I grasped
> > several examples like watchdog/pcwd.c; watchdog/w83977f_wdt.c;
> > watchdog/of_xilinx_wdt.c and saw that I can use it in meaning "the card initiated reset.
> > After the WDT is overflowed it sets WDFLAG, so I can use it.
> > It is more useful while debugging and if it is doubtful I can drop it.
> The usual reaction to a watchdog timer event is a reset, so I am somewhat
> doubtful if this is of any use in practice, other than maybe to show that it
> isn't working.
>
> Anyway, I always dislike it when people point out other wrong usages of an API
> (or anything, really) as argument to do the same. Speeding isn't legal either,
> no matter how many people do it. FWIW, the wrong usages you pointed out should
> in my opinion be removed, and if Wim agrees I'll be happy to submit patches to
> do it.
>
> If you need debugging information, there is always debugfs. There should be
> no need to hijack an API which is supposed to be used for something else.
>
> Guenter

I'll drop it

--
Regards,
Ivan Khoronzhuk
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/