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From: Guenter Roeck <linux@roeck-us.net>
To: Michal Simek <monstr@monstr.eu>
Cc: Michal Simek <michal.simek@xilinx.com>,
	linux-kernel@vger.kernel.org, Wim Van Sebroeck <wim@iguana.be>,
	linux-watchdog@vger.kernel.org
Subject: Re: [PATCH 3/3] watchdog: xilinx: Add WDIOC_SETTIMEOUT ioctl function
Date: Thu, 30 May 2013 08:03:06 -0700	[thread overview]
Message-ID: <20130530150306.GA29508@roeck-us.net> (raw)
In-Reply-To: <51A7635A.8070300@monstr.eu>

On Thu, May 30, 2013 at 04:34:02PM +0200, Michal Simek wrote:
> On 05/30/2013 04:21 PM, Guenter Roeck wrote:
> > On Thu, May 30, 2013 at 04:15:45PM +0200, Michal Simek wrote:
> >> On 05/30/2013 04:07 PM, Guenter Roeck wrote:
> >>> On Thu, May 30, 2013 at 02:26:04PM +0200, Michal Simek wrote:
> >>>> Standard watchdog programs try to setup timeout
> >>>> via ioctl and this functionality should be implemented.
> >>>> Timeout value is hardcoded in the hardware but
> >>>> based on Documentation/watchdog/watchdog-api.txt
> >>>> can return the real timeout used in the same variable.
> >>>>
> >>>> Signed-off-by: Michal Simek <michal.simek@xilinx.com>
> >>>> ---
> >>>>  drivers/watchdog/of_xilinx_wdt.c | 1 +
> >>>>  1 file changed, 1 insertion(+)
> >>>>
> >>>> diff --git a/drivers/watchdog/of_xilinx_wdt.c b/drivers/watchdog/of_xilinx_wdt.c
> >>>> index 79f358c..a3bbe72 100644
> >>>> --- a/drivers/watchdog/of_xilinx_wdt.c
> >>>> +++ b/drivers/watchdog/of_xilinx_wdt.c
> >>>> @@ -253,6 +253,7 @@ static long xwdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> >>>>  		xwdt_keepalive();
> >>>>  		return 0;
> >>>>
> >>>> +	case WDIOC_SETTIMEOUT:
> >>>>  	case WDIOC_GETTIMEOUT:
> >>>>  		if (no_timeout)
> >>>>  			return -ENOTTY;
> >>>
> >>> Watchdog programs should check ident.options before trying to set the timeout.
> >>> If they don't, there is an application bug. I don't think it is a good idea
> >>> to start hacking the kernel to work around application bugs.
> >>
> >> Based on Documentation/watchdog/watchdog-api.txt
> >>
> >> "For some drivers it is possible to modify the watchdog timeout on the
> >> fly with the SETTIMEOUT ioctl, those drivers have the WDIOF_SETTIMEOUT
> >> flag set in their option field.  The argument is an integer
> > 
> > Yes, but WDIOF_SETTIMEOUT is not set in the driver's option field.
> 
> ok. It means I should probably enable it.
> 
I am missing your point. Applications should not try to write the timeout
since WDIOF_SETTIMEOUT is not set. Any application doing it anyway is buggy
and should be fixed.

Guenter

  reply	other threads:[~2013-05-30 15:02 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-05-30 12:26 [PATCH 1/3] watchdog: xilinx: Fix driver header Michal Simek
2013-05-30 12:26 ` [PATCH 2/3] watchdog: xilinx: Setup the origin compatible string Michal Simek
2013-05-30 14:00   ` Guenter Roeck
2013-05-30 14:04     ` Michal Simek
2013-05-30 12:26 ` [PATCH 3/3] watchdog: xilinx: Add WDIOC_SETTIMEOUT ioctl function Michal Simek
2013-05-30 14:07   ` Guenter Roeck
2013-05-30 14:15     ` Michal Simek
2013-05-30 14:21       ` Guenter Roeck
2013-05-30 14:34         ` Michal Simek
2013-05-30 15:03           ` Guenter Roeck [this message]
2013-05-30 15:12             ` Michal Simek
2013-05-30 15:25               ` Guenter Roeck
     [not found]                 ` <CAHTX3dJ9fDJ6ggMGcF5v1vdcruMqnV4fv_6eP3U3DgOUfm8r+w@mail.gmail.com>
2013-05-30 22:08                   ` Wim Van Sebroeck
2013-05-31  5:48                     ` Michal Simek
2013-05-30 12:30 ` [PATCH 1/3] watchdog: xilinx: Fix driver header Venu Byravarasu
2013-05-30 12:32   ` Michal Simek
2013-05-30 14:26     ` Alejandro Cabrera

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