RE: [PATCH 0/2] lan78xx: Remove trailing underscores from macros

From: Ronnie.Kunin
Date: Tue Sep 06 2016 - 22:00:17 EST


Microchip's internal convention is for register (offset) definitions to be capitalized (i.e.: MY_REGISTER). Our convention for bits (position) definitions within a register is to carry as a prefix the name of the register and suffix it with the bit name and adding a trailing underscore (i.e. MY_REGISTER_MY_BIT_). The trailing underscore is what easily lets us distinguish a bit from a register definition when reading code. We have been using this convention for many years and has worked very well for us across all projects (by now hundreds).

>Is there anything other than a one-time cost
>to apply these? Is the same code used for
>other platforms?
Yes, a single header file with the definition of registers and bits is shared (either as a standalone file or with its contents pasted into a native environment "carrier" header file) across all drivers (and other non driver software projects as well) for the same device. So a change like this indeed has a high cost for Microchip and we'd rather not do this unless it is an absolutely mandated requirement.

Thanks,
Ronnie
________________________________________
From: Joe Perches [joe@xxxxxxxxxxx]
Sent: Tuesday, September 06, 2016 9:18 PM
To: Woojung Huh - C21699; netdev@xxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx
Cc: f.fainelli@xxxxxxxxx; UNGLinuxDriver; linux-kernel@xxxxxxxxxxxxxxx
Subject: Re: [PATCH 0/2] lan78xx: Remove trailing underscores from macros

On Tue, 2016-09-06 at 23:19 +0000, Woojung.Huh@xxxxxxxxxxxxx wrote:
> > Joe Perches (2):
> > lan78xx: Remove locally defined trailing underscores from defines and uses
> > microchipphy.h and uses: Remove trailing underscores from defines and
> > uses
> >
> > drivers/net/phy/microchip.c | 4 +-
> > drivers/net/usb/lan78xx.c | 368 +++++++--------
> > drivers/net/usb/lan78xx.h | 1068 +++++++++++++++++++++-----------------
> > ----
> > include/linux/microchipphy.h | 72 +--
> > 4 files changed, 756 insertions(+), 756 deletions(-)
>
>
> Because there is no specific rule how to name defines, I'm not sure it is worth to change 1000+ lines.
> It may be better to set guideline for new submissions.
>
> Welcome any comments.

Generally, more conforming to norms is better.
These FOO_ uses are non-conforming.

Is there anything other than a one-time cost
to apply these? Is the same code used for
other platforms?