RE: [PATCH v3 2/4] bus: fsl-mc: add restool userspace support

From: Ioana Ciornei
Date: Fri Mar 23 2018 - 16:14:00 EST


> >
> > >
> > > On Fri, Mar 23, 2018 at 10:38:56AM -0500, Ioana Ciornei wrote:
> > > > +#include "fsl-mc-private.h"
> > > > +
> > > > +#define FSL_MC_BUS_MAX_MINORS 1
> > >
> > > As you only need/want one character device here, why not just use
> > > the misc device api? It's much simpler, and handles all of the
> > > housekeeping for you correctly. It also means I don't have to audit
> > > all of your chardev code to verify it is correct :)
> >
> > I have considered the misc device api but the fsl-mc bus, since it is
> > a platform driver, is probing before the misc char driver.
>
> How? The misc code is just "core code" there's nothing to "probe" here.
> Is this an init-call ordering issue somehow? A platform driver probe should be
> after the misc core is initialized. And if not, you can always defer your probe.

Sorry for the previous improper wording. I have tested again using the misc device api and indeed the devices on the fsl-mc bus are probing before the misc core is initialized but I am able to complete the misc registration deferring the probe the first time.

I will update the patch set and send a new version.

Ioana C


>
> thanks,
>
> greg k-h