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

[Jakob Oestergaard <jakob@unthought.net>]

On Tue, Feb 18, 2003 at 09:24:15PM -0800, Rusty Lynch wrote:
> My original proposal raised a couple of issues with sysfs that make it
> difficult to move completely from the current watchdog model documented in 
> watchdog-api to a completely sysfs based implementation.
> 
> Specifically, sysfs needs:
> * persistent file permissions
> * a way to forward ioctl's or in some way represent a device node in sysfs

Something as simple as a watchdog should not need ioctls, IMO.  (Nothing
should need them, but let's take one battle at a time...)

How about using sysfs and specifically - now that we have a collection
of drivers which are simple enough to not need the mistake that ioctls
are - making sure that they work as before, using only device files and
no magic ioctls ?

I shall happily volunteer to delete the 10 lines of code from
sbc60xxwdt.c to make it compliant to the "no ioctls - equivalent
functionality" idea  ;)

I know that there is ioctl support in the existing drivers - but I have
not yet seen a driver which needed it.   "needed" in the sense that
equivalent functionality could not have been created using dev files
alone.

Also, the amount of userspace which will break because of missing ioctl
functionality will be absolutely *minimal*.  There's not a lot of
watchdog software out there, and porting whatever software uses ioctls
to use sane interfaces instead, should be doable.  I don't think anyone
would get terribly upset if this change was made as a 2.4->2.6
transition thing.

If ioctls are kept in watchdog drivers for 2.6, they can't go away until
2.8/3.0/whatever.

-- 
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