Re: [PATCH 1/2] Revert "include/uapi/drm/amdgpu_drm.h: use __u32 and __u64 from <linux/types.h>"

[Mikko Rapeli]

Cc'ing lkml.

On Fri, Aug 19, 2016 at 09:18:24PM -0500, Ken Phillis Jr wrote:
> On Fri, Aug 19, 2016 at 8:46 PM, Rob Clark <robdclark@xxxxxxxxx> wrote:
> 
> > perhaps, but if the target audience for driver specific APIs is
> > libdrm/mesa, which already uses stdint types, then I fail to see the
> > point..
> >
> > It is a bit difference scenario for some of the core kms ioctls which
> > are not driver specific..  but most of the driver specific gpu related
> > ioctls tend to be rather complex and not intended for use by something
> > other than libdrm/mesa.
> >
> > BR,
> > -R
> >
> 
> I personally do not see the reason to break user space API in the first
> place.
> I know for a fact that the include file ( linux/types.h ) mentioned by the
> patch
> supports C99 integer data types since Linux Kernel Version 2.2.0. This makes
> the patch that got reverted completely meaningless since the only reason to
> make this change in the first place would be if the developer intends on
> backporting the driver to kernels older than version 2.2.0.

In userspace linux/types.h does not provide these integer data types to avoid
conflict with libc ones.

Thus several uapi headers fail to compile in userspace. Fix is to either
include libc side stdint.h in userspace but that was rejected by kernel
developers including Linus who are in favor of kernel specific double
underscore types.

-Mikko