On Wed, 5 Dec 2007 22:00:03 +0100
Sam Ravnborg <[EMAIL PROTECTED]> wrote:
> On Tue, Dec 04, 2007 at 09:04:33PM -0600, Jay Cliburn wrote:
> > Sam,
> >
> > This piece of the top-level Makefile in current git causes an
> > out-of-tree driver Makefile to fail.
> >
> > 101 ifdef O
> > 102 ifeq ("$(origin O)", "command line")
> > 103 KBUILD_OUTPUT := $(O)
> > 104 endif
> > 105 endif
> >
> > The out-of-tree driver Makefile contains an O=... directive that
> > (correctly) does _not_ specify the kernel source dir, and apparently
> > isn't overridden by the command line either. If in the above
> > Makefile snippet I change "command line" to "file", my out-of-tree
> > make succeeds. What do you think about allowing O= to come from a
> > file in addition to the command line?
>
> When you change "command line" to "file" you actually makes kbuild
> ignore the O=... value which is why it succeeds.
I'm puzzled by your statement. Isn't the opposite true? When using
"command line", doesn't the following happen?
1. My makefile sets O=/foo
2. My makefile invokes your makefile with O=/foo
3. Your makefile ignores my O=/foo because it requires O=/foo to
originate from the command line
4. KBUILD_OUTPUT never gets set to /foo and we hit the error
OTOH, if I use "file":
1. My makefile sets O=/foo
2. My makefile invokes your makefile with O=/foo
3. Your makefile accepts my O=/foo because it requires O=/foo to
originate from another makefile
4. KBUILD_OUTPUT gets set to /foo and my make succeeds
This all used to work the last time I tried it, which was sometime
during 2.6.23 development, IIRC. Isn't the current structure going to
break just about all out-of-tree driver builds?
Jay
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