On Tue, 10 Feb 2009, Mauro Carvalho Chehab wrote:
> > I did some more testing and the bug disappears in kernel 2.6.25. Also, if I
> > just run 'make', then the .config file it produces is fine. I wonder if it
> > isn't a bug in menuconfig itself.
>
> It seems to be a bug at the Kbuild, fixed on Feb, 2008, on this changeset:
> commit 587c90616a5b44e6ccfac38e64d4fecee51d588c (attached).
>
> As explained, after the patch description, the value for the Kconfig var, after
> the patch, uses this formula:
>
> (value && dependency) || select
It's odd that the patch is for "fix select in combination with default",
yet there is no select used for CX88_DVB. I think what you've done with
CX88_MPEG is something that nothing else in has used before, which made use
of the behavior introduced by this patch in a new way.
> And there there's no select, the value of CONFIG_CX88_MPEG is determined by:
> ('y' && dependency)
>
> The most complex case is when we have CX88 defined as:
> CX88 = 'y'
>
> if both CX88_DVB and CX88_BLACKBIRD are defined as 'm' (or one of them is 'n'
> and the other is 'm'), then CX88_MPEG is defined as:
> CX88_MPEG = 'm'
>
> If one of CX88_DVB or CX88_BLACKBIRD is defined as 'y'; then we have:
> CX88_MPEG = 'y'
>
> If both are 'n', we have:
> CX88_MPEG = 'n'
>
> So, it seems that, after commit 587c90616a5b44e6ccfac38e64d4fecee51d588c,
> everything is working as expected. We just need to provide a hack at the
> out-of-tree build system for kernels that don't have this commit applied.
I still think using select is better. What Roman Zippel was talking about
was the mess with select and the tuner drivers. I agree that's a mess and
there are better ways to do it without using select. But the MPEG module
is like a library used by just DVB and BLACKBIRD. It seems like the ideal
case for using select.
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
