[U-Boot] [PATCH 1/2] kbuild: Fix a false error of generic board support

[Masahiro Yamada]

Hi Marek, Tom,


On Wed, 17 Dec 2014 10:52:32 -0500
Tom Rini <trini at ti.com> wrote:

> On Wed, Dec 17, 2014 at 02:04:32AM +0100, Marek Vasut wrote:
> > On Wednesday, December 17, 2014 at 12:56:46 AM, Tom Rini wrote:
> > > On Tue, Dec 16, 2014 at 02:56:44PM -0600, mgerlach wrote:
> > > > Hello Masahiro Yamada,
> > > > 
> > > > Even the with this patch, we encountered a false error of generic board
> > > > support.  The problem was very interrmittent for us, but we were able
> > > > to debug the problem to performing builds on EXT3 file systems which
> > > > have a time stamp resolution of one second.  To reproduce the problem,
> > > > touch ./include/config/auto.conf and .config on a configured uboot tree
> > > > on an EXT3 file system.
> > > > 
> > > > The patch below fixes the problem for us.
> > > 
> > > This makes an odd race condition problem I run into when doing massively
> > > paralell builds worse :(  With MAKEALL no ARM boards build (ARCH wasn't
> > > set in time so it tried arch//Makefile for something) and buildman was
> > > also broken in a bunch of places.
> > 
> > Let me just chime in, I recall I did report something possibly similar some time 
> > ago [1]. I did not manage to put a finger on this issue though and I can no 
> > longer trigger it.
> > 
> > [1] http://lists.denx.de/pipermail/u-boot/2013-June/157481.html
> 
> No, my problem was introduced with the switch to Kbuild itself.


Marek's problem is unrelated to this issue.  (2013-June is before Kbuild)


York Sun also reported the similar build error in this thread.
http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/203331/focus=203468

This is really related to what Mathew saw, I think.


Some bug reports imply "autoconf_is_current" is not working on some cases
although I have never been able to reproduce the problem on my box.

I guess it is almost time for further build-system refactoring.


Best Regards
Masahiro Yamada