Simple Read operation on a misc device driver

[Fernando Apesteguía]

El 19/04/2014 18:52, "L. Alberto Giménez" <agimenez at sysvalve.es> escribió:
>
> On Fri, Apr 18, 2014 at 02:35:53PM -0700, Greg KH wrote:
> > On Fri, Apr 18, 2014 at 06:30:44PM -0300, Aldo Esteban Paz wrote:
> > > For the Eudyptula's Chanllenge Task 6, i need to write a misc device
> > > driver with simple read/write operations.
> > >  The following was the answer to part of my code:
> > >
> > > > static char eid[] = EUDYPTULAID;
> > > >
> > > > static ssize_t misc_device_read(struct file *file, char __user *buf,
> > > >                                         size_t count, loff_t *ppos)
> > > > {
> > > >         if (*ppos == sizeof(eid))
> > > >                 return 0;
> > > >         else
> > > >                 if (*ppos != 0 || count < sizeof(eid))
> > > >                         return -EINVAL;
> > > >
> > > >         if (copy_to_user(buf, eid, sizeof(eid)))
> > > >                 return -EINVAL;
> > > >
> > > >         *ppos = sizeof(eid);
> > > >
> > > >         return *ppos;
> > > > }
> > >
> > > This whole function can be made much more "simple" and reduced to one
> > > single line {hint} (It's just a "simple" function call {hint}).
> > >
> > > Anyone know that "single" function?
> >
> > Yes, but you really should do your own research for stuff like this,
> > that's what the challenge is all about, not asking others to do it for
> > you :(
>
> I'm curious about this. I didn't get the simple, one-line function call
feedback and
> my task was accepted with a regular function definition, similar to the
one from the
> OP.

That feedback may come in the next tasks ;)

>
> --
> L. Alberto Giménez
> GnuPG key ID 0xDD4E27AB
>
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