Re: [PATCH linux-next] Documentation: mic: mpssd: Disable mpssd builds for kernels < 3.13

[Andrew Morton <akpm@linux-foundation.org>]

On Tue, 23 Sep 2014 19:23:39 -0400 Peter Foley <pefoley2@pefoley.com> wrote:

> On Tue, Sep 23, 2014 at 6:59 PM, ashutosh dixit
> <ashutosh.dixit@intel.com> wrote:
> > Correct, if things in Documentation will be compiled against the headers
> > in the kernel source tree then this patch is not required. However,
> > Andrew had reported the following compile error:
> >
> >> In file included from Documentation/mic/mpssd/sysfs.c:21:
> >> Documentation/mic/mpssd/mpssd.h:55:30: error: linux/virtio_ids.h: No such file or directory
> >
> > which made it appear to us that Documentation was being compiled against
> > headers installed on the system, not headers in the kernel source
> > tree. The patch was submitted to address this latter case, but if that
> > does not occur it is not required.
> >
> Alright, if you want to handle the case where somebody is trying to
> build against old and incompatible headers,
> just have a #error "Your kernel headers are too old, at least 3.13 is
> required" at the top of mpssd.c instead of having it fail at runtime.
> 

This build error is caused by compiling mpssd prior to `make
headers_install'.

There's really no reason to check the kernel version.  If someone
transplants mpssd out of its distributed kernel and into some older
kernel then a miscompile is their problem - their backport is
incomplete.