Re: [PATCH 3/5] drivers:usb:fsl: Replace macros with enumerated type

[Greg KH <gregkh@linuxfoundation.org>]

On Sun, May 31, 2015 at 12:11:18AM -0700, Joe Perches wrote:
> On Sun, 2015-05-31 at 15:50 +0900, Greg KH wrote:
> > On Tue, May 26, 2015 at 05:15:48PM +0530, Nikhil Badola wrote:
> > > Replace macros with enumerated type to represent usb ip
> > > controller version
> > > 
> > > Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
> > > ---
> > >  include/linux/fsl_devices.h | 13 ++++++++-----
> > >  1 file changed, 8 insertions(+), 5 deletions(-)
> > > 
> > > diff --git a/include/linux/fsl_devices.h b/include/linux/fsl_devices.h
> []
> > > +enum fsl_usb2_controller_ver {
> > > +	FSL_USB_VER_OLD = 0,
> > > +	FSL_USB_VER_1_6,
> > > +	FSL_USB_VER_2_2,
> > > +	FSL_USB_VER_2_4,
> > > +	FSL_USB_VER_2_5,
> > > +};
> > 
> > Don't you want to change that function that uses these to return the
> > enumerated type and not an integer?
> > 
> > Also, I don't think the C standard forces the non-numberd values to be
> > sequential,
> 
> Then you haven't read the standard in awhile and you likely forgot.
> 
> 6.7.2.2
> If the first enumerator has no =, the value of its enumeration constant
> is 0. Each subsequent enumerator with no = defines its enumeration
> constant as the value of the constant expression obtained by adding 1 to
> the value of the previous enumeration constant.

Ah, you are right, I did forget.

But if you are wanting to use the "numerical" value of these, please be
explicit when defining it.  Otherwise someone might think it was just
fine to put a new entry in the middle of the list.

thanks,

greg k-h