Re: [DRIVER][RFC] SC1200 Watchdog driver

Zwane Mwaikambo
2002-02-21T12:43:57Z

On Thu, 21 Feb 2002, Jeff Garzik wrote:

> now, a policy question -- do you want to fail or simply put to sleep
> multiple openers? if you want to fail, this should be ok I think. if
> you want to sleep, you can look at sound/oss/* in 2.5.x or
> drivers/sound/* in 2.4.x for some examples of semaphore use on open(2).

i think the following would be ok here.

[...]
if (down_interruptible(&open_sem))
return -ERESTARTSYS;
[...]

> Here's a big one, I still don't like this lack of probing in the
> driver. Sure we have "probed elsewhere", but IMO each driver like this
> one needs to check -something- to ensure that SC1200 hardware is
> present. Otherwise, a random user from a distro-that-builds-all-drivers
> might "modprobe sc1200_watchdog" and things go boom.

The actual SuperIO chip the SC1200 is based on is fully PnP so we can
easily do a search without frobbing hardware. To support non PnP mode, we
could find a register with a default value which isn't 0xFF or 0x00, i
reckon that would work quite well.

Regards,
Zwane Mwaikambo