On Thursday 1 February 2007 00:39:14 you wrote:
> On Tue, 30 Jan 2007 21:30:29 +0000
> Simon Arlott <[EMAIL PROTECTED]> wrote:
>
> > +static int cxacru_proc_read(struct usbatm_data *usbatm_instance,
> > + struct atm_dev *atm_dev, loff_t * pos, char *page)
> > +{
> > + struct cxacru_data *instance = usbatm_instance->driver_data;
> > + u32 *cxinf = instance->cxinf_status;
> > + int left = *pos;
> > +
> > + if (!left--)
> > + return sprintf(page, "# %s\n", usbatm_instance->description);
> > +
> > + if (!left--) {
> > + if (cxinf[CXINF_LINE_STATUS] == 5) {
> > + return sprintf(page, "# UP %u/%u\n",
> > + cxinf[CXINF_DOWNSTREAM_RATE],
> > + cxinf[CXINF_UPSTREAM_RATE]);
> > + } else {
> > + return sprintf(page, "# DOWN\n");
> > + }
> > + }
>
> hm, how well-tested was this proc interface? The pread() and lseek()
> behaviour might be strange.
>
> I guess as long as it doesn't oops, hang or anything like that then it'll
> be OK. Anyone who does anything apart from a single big-fat-read from a
> procfile has a good chance of getting into trouble :(
All the ATM drivers seem to do it like this. That doesn't mean they are
right of course! But I never saw anyone complain on the ATM mailing list.
On the other hand, why does Simon want this? If he has written a user space
tool that extracts bits from the proc file (eg: to tell users what's going
on) then he could run into trouble, depending on how he implements it.
Ciao,
Duncan.
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