On 30.05.2015 18:46, Russell King - ARM Linux wrote:
On Sat, May 30, 2015 at 05:37:57PM +0200, Mikko Rapeli wrote:
Fixes userspace compilation error:
drm/exynos_drm.h:30:2: error: unknown type name ‘uint64_t’
Signed-off-by: Mikko Rapeli <mikko.rapeli@xxxxxx>
This is another thing which we need to address. We should not be using
unsigned int/unsigned long/uintXX_t/etc in here, but the __uXX and __sXX
types.
The lesson learned from other DRM developers is that using these types
simplifies the API especially when it comes to the differences between
32-bit and 64-bit machines, and compat applications.
Note that drm/drm.h is all that should need to be included - drm/drm.h
takes care of including linux/types.h when building on Linux platforms.
(note: if your compiler doesn't set __linux__ then you're probably not
using the proper compiler...)
Using types that differs on 32-bit and 64-bit machines for a kernel
interface is indeed a rather bad idea. This not only includes longs, but
pointers as well.
But the int8_t, int16_t int32_t, int64_t and their unsigned counterparts
are defined in stdint.h which is part of the ISO/IEC 9899:1999 standard,
similar is true for size_t.
The __uXX, __sXX and _kernel_size_t types are linux specific as far as I
know.
For best interoperability and standard conformance I think that
definitions from the C standard we use should out-rule linux specific
definitions.
Additional to that "linux/types.h" is not part of the uapi as far as I
know, so including it in a header which is part of the uapi should be
forbidden.
So this is a NAK from my side for the whole series, userspace programs
should include <stdint.h> for the definition of the ISO/IEC 9899:1999
standard types if necessary.
Regards,
Christian.
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