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SubjectRe: [PATCH 1/2] Add c2 port support.
On Wed, Oct 22, 2008 at 01:01:50PM -0700, Andrew Morton wrote:
> > > <wonders what local_irq_disable() is supposed to achieve on SMP>
> >
> > The SMP is achieved by mutex_lock(), the local_irq_disable() is used
> > to avoid interructions in code execution. C2 port has very stringent
> > timings.
>
> Please add code comments explaning this (unless I missed them).

Ok.

> > + if (!ret)
> > + return ERR_PTR(-ENOMEM);
>
> ^^ leaks c2dev

Fixed.

> > + if (unlikely(!c2dev->dev)) {
> > + ret = -ENOMEM;
> > + goto error_device_create;
> > + };
>
> ^

Fixed.

> > > What I haven't yet got my head around is this:
> > >
> > > Currently this code supports only flash programming through sysfs
> > > interface but extensions shoud be easy to add.
> > >
> > > is that really what we want to use sysfs for? As the prime interface
> > > to a device driver (or is it a bus driver?) Didn't we used to use
> > > device nodes for that sort of thing?
> >
> > I decided to use this interface since the C2 ports are simple and very
> > easy to manage with such files abstraction.
>
> well.. what _is_ the implemented interface? What alternatives were
> considered and why were they judged inappropriate? What interfaces do
> any similar in-tree drivers use?

Well... main reasons in using sysfs support are:

* no more char devices and new ioctls to define,

* the microcontrollers on-board flash can be easily programmed by
using only the "echo" and "cat" commands, so no more tools are needed
and even simply busybox can be used.

> > Whould you like I repropose the code with the fixed issues for your
> > review?

I repost the code.

Thanks,

Rodolfo

--

GNU/Linux Solutions e-mail: giometti@enneenne.com
Linux Device Driver giometti@linux.it
Embedded Systems phone: +39 349 2432127
UNIX programming skype: rodolfo.giometti


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