Re: [PATCH V3 04/12] misc: xilinx_sdfec: Add open, close and ioctl

From: Greg KH
Date: Sat May 04 2019 - 10:42:07 EST


On Sat, May 04, 2019 at 10:35:02AM -0400, Arnd Bergmann wrote:
> On Thu, May 2, 2019 at 1:23 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > On Sat, Apr 27, 2019 at 11:04:58PM +0100, Dragan Cvetic wrote:
> > > Add char device interface per DT node present and support
> > > file operations:
> > > - open(),
> > > - close(),
> > > - unlocked_ioctl(),
> > > - compat_ioctl().
> >
> > Why do you need compat_ioctl() at all? Any "new" driver should never
> > need it. Just create your structures properly.
>
> The function he added was the version that is needed when the structures
> are compatible. I submitted a series to add a generic 'compat_ptr_ioctl'
> implementation that would save a few lines here doing the same thing,
> but it's not merged yet.
>
> Generally speaking, every driver that has a .ioctl() function should also
> have a .compat_ioctl(), and ideally it should be exactly this trivial
> version.

Ok, for some reason I thought if there was no need for a compat ioctl
(i.e. no pointer mess), then no need for a callback at all.

thanks,

greg k-h