Re: [PATCH 01/10] lis3lv02d: avoid divide by zero due to unchecked

[Andrew Morton]

On Mon, 1 Aug 2011 23:11:17 +0200
Christian Lamparter <chunkeey@xxxxxxxxxxxxxx> wrote:

> On Monday, August 01, 2011 10:29:06 PM Andrew Morton wrote:
> > On Mon, 25 Jul 2011 17:16:23 +0200
> > __ric Piel <eric.piel@xxxxxxxxxxxxxxxx> wrote:
> > 
> > > +static int lis3lv02d_get_pwron_wait(struct lis3lv02d *lis3)
> > > +{
> > > +	int div = lis3lv02d_get_odr();
> > > +
> > > +	if (WARN_ONCE(div == 0, "device returned spurious data"))
> > > +		return -ENXIO;
> > > +
> > > +	/* LIS3 power on delay is quite long */
> > > +	msleep(lis3->pwron_delay / div);
> > > +	return 0;
> > > +}
> > 
> > The WARN_ONCE may not be very useful.  The user gets worried, might
> > report it (often to a distro, not to you!).  But we won't actually *do*
> > anything with the information?
> The sensor is used to park the hdd in case of an "accident". However,
> if the sensors is not working, the user should at least get a WARN
> that something is very wrong, right?

Well if we're doing this for the user's benefit (most WARNs are for developers)
then the message should be user-useful.  That one isn't, really.

Can we come up with some text which is more useful to the user/operator and
won't require him/her/it to send emails and raise bug reports?

Also, the stack trace which WARN emits is not useful in this application?
--
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/