Re: [PATCH 2/2] xhci: Rename SEGMENT_SIZE and SEGMENT_SHIFT as the former is used in a.out.h

[David Howells <dhowells@redhat.com>]

Sarah Sharp <sarah.a.sharp@linux.intel.com> wrote:

> I guess my question is a deeper one: do we need to rename all the xHCI
> macros to have the XHCI_ prefix, in order to avoid future collision?
> For example, one of the macros is MAX_HC_PORTS, which could possibly be
> used by other host drivers in the future.

Hmmm...

I suspect the question is whether your symbols are likely to collide with
core symbols rather than symbols of unrelated drivers - after all, you're
unlikely to be #including the headers of those drivers.

I personally prefer to prefix the names of symbols in drivers with something
consistent for that driver to reduce namespace collisions - but I know not
everyone cares about that.  Linux doesn't have much of a policy in this area
though.  I also like it because it makes tags easier to use (fewer definitions
of the same symbol).

Whether you should go back and rename existing xHCI functions, I don't know.
I'd be tempted to leave it for now unless there's some collision.  However,
things like MAX_HC_PORTS does seem a little generic.  Further #define
collisions go unnoticed under some circumstances.  Two obvious cases are (a)
redefinition of a symbol because it happens to be the same value and (b) where
the second one is accidentally suppressed because it is wrapped in a
conditional.

Perhaps we should move to C++ and use namespaces;-)

David