On 03/23/2015 12:58 PM, Richard Cochran wrote:

On Mon, Mar 23, 2015 at 12:02:03PM -0400, Chris Metcalf wrote:

quoted

quoted

This driver is 64-bit only.  Would it make more sense to just change
the accessors from gettime/settime to gettime/settime64 and nothing
else, i.e. rely on the current behavior that timespec and timespec64
are the same type, and trust the compiler to fail it if somehow someone
tried to build this driver into a 32-bit kernel?

On the one hand, I think the best way would be for
gxio_mpipe_get/set_timestamp to also take a timespec64, because it
makes the width clear.  With a plain old timespec, you have to
remember whether you are 64 bit or not.  However, but I couldn't tell
if changing gxio_mpipe_get/set_timestamp would work for other callers
or not.

If you're suggesting changing the gxio_mpipe_xxx_timespec routines
to take a timespec64, that sounds reasonable to me, particularly in
conjunction with your new gettime64 etc API.

As far as I know, the tilegx driver is the only client of those gxio
routines.

If the driver is 64 bit only, shouldn't that be reflected in the
Kconfig?

Well, the tilegx driver is only supported for the tilegx architecture,
which is only 64-bit for kernel-space.  It may be a bit confusing
because the actual driver is tile_net, which has separate implementations
for tilegx (64-bit) and tilepro (32-bit).  It's not immediately clear how
to make that more obvious.

On the other hand, I wouldn't mind the change you suggest, if it were
super obvious that the code is 64 bit only.  It was not obvious to me.

I guess that brings us back to changing the gxio_xxx APIs.

-- 
Chris Metcalf, EZChip Semiconductor
http://www.ezchip.com