Re: [PATCH][RFC] Proposal for a new watchdog interface using sysfs

Rusty Lynch (rusty@linux.co.intel.com)
12 Feb 2003 23:32:38 -0800


On Wed, 2003-02-12 at 20:27, Daniel Pittman wrote:
> On 12 Feb 2003, Rusty Lynch wrote:
> > The following is a proposal for a new sysfs based watchdog interface
> > to be used as a replacement for the current char device w/ ioctl api
> > as described in Documentation/watchdog-api.txt.
>
> [...]
>
> > Where each these files to the following ==>
> >
> > start (RO)
> > - show: starts watchdog count
>
> This would be much better as a store -- that way 'cat /.../watchdog0/*'
> will not activate the watchdog. A more deliberate action is safer for
> forgetful admins, such as me.
>

Sounds logical. My reasoning was more of a coin toss.

> [...]
>
> > status (RO)
> > - show: prints the current status value
> >
> > bootstatus (RO)
> > - show: same as 'status', but valid for just after the last reboot.
>
> [...]
>
> > enable (RW)
> > - show: prints 0 or 1 to indicate if the wdt is enabled
> > - store: expects 0 or 1 to disable or enable the wdt
>
> Isn't this the same information as the 'status' and 'start' members?
>
> Daniel

Now that think about it, enable really is the same as start/stop, but
the status is still something different. I didn't really talk about it,
but my intent was to provide the information currently available from
the WDIOC_GETSTATUS ioctl, which is a value composed of the following
flags:

#define WDIOF_OVERHEAT 0x0001 /* Reset due to CPU overheat */
#define WDIOF_FANFAULT 0x0002 /* Fan failed */
#define WDIOF_EXTERN1 0x0004 /* External relay 1 */
#define WDIOF_EXTERN2 0x0008 /* External relay 2 */
#define WDIOF_POWERUNDER 0x0010 /* Power bad/power fault */
#define WDIOF_CARDRESET 0x0020 /* Card previously reset the CPU */
#define WDIOF_POWEROVER 0x0040 /* Power over voltage */
#define WDIOF_SETTIMEOUT 0x0080 /* Set timeout (in seconds) */
#define WDIOF_MAGICCLOSE 0x0100 /* Supports magic close char */
#define WDIOF_KEEPALIVEPING 0x8000 /* Keep alive ping reply */

I debated with myself if each of these flags should be broke out into
their own file, and I'm still not sure if it is better to keep the
status as a single file.

>
> --
> A cathedral, a wave of a storm, a dancer's leap,
> never turn out to be as high as we had hoped.
> -- Marcel Proust
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