Re: Linux 2.6.26-rc1

From: Alistair John Strachan
Date: Sun May 04 2008 - 12:34:02 EST


On Sunday 04 May 2008 17:09:04 Robin Holt wrote:
> On Sun, May 04, 2008 at 02:56:14PM +0100, Alistair John Strachan wrote:
> > On Sunday 04 May 2008 13:30:08 Robin Holt wrote:
> > > On Sat, May 03, 2008 at 10:53:22PM +0100, Alistair John Strachan wrote:
> > > > On Saturday 03 May 2008 22:47:38 Alistair John Strachan wrote:
> > > > > On Saturday 03 May 2008 20:38:20 Linus Torvalds wrote:
> > > > > > So go out and test it.
> > > >
> > > > [snip]
> > > >
> > > > > Why is this option acting like CONFIG_EMBEDDED and not like
> > > > > basically every other subsystem where I can turn ON support for
> > > > > hardware, but by default it's OFF? (Obviously in my hasty oldconfig
> > > > > run I just went with the default.)
> > > >
> > > > Amazingly, even if I say Y to this option and disable all tuners, it
> > > > still tries (and fails) to compile this file. What is pulling in this
> > > > tuner-core dependency?
> > >
> > > What if you change CONFIG_MEDIA_TUNER to a 'n'
> >
> > This isn't a menu-visible option. Your hint does explain why it turns
> > itself on, however:
> >
> > config MEDIA_TUNER
> > tristate
> > default DVB_CORE || VIDEO_DEV
> > depends on DVB_CORE || VIDEO_DEV
> >
> > I have DVB_CORE=n and VIDEO_DEV=y. VIDEO_DEV is:
> >
> > config VIDEO_DEV
> > tristate "Video For Linux"
> >
> > So if you enable Video For Linux, the tuner-core is automatically built,
> > even if no tuners are selected? Surely that's wrong..
>
> That is probably correct. Video For Linux is used for capturing video
> streams. The fact that you can get this invalid config to fail to build
> should be reported to the v4l folks and let them fix it up.

a) He's already on CC
b) No config I have posted was invalid
c) There are two (possibly three) entirely separate issues

You've got the wrong end of the stick here. I'm not saying V4L isn't required
for MEDIA_TUNER, but MEDIA_TUNER should not be a dependency of V4L and so
should NOT be unconditionally enabled.

The first issue is obviously the build error, which can be resolved by adding
a dep on I2C to MEDIA_TUNER, but given the recent churn there I'll leave that
to Mauro.

The second issue is the fact that the MEDIA_TUNER option is transparent and
not user selectable, building code that is probably not required in some
kernel configurations (tuner code depends on V4L, but surely not the other
way around.. MEDIA_TUNER should be able to be n when VIDEO_DEV is y).

The final issue is more of a matter of personal taste, which refers to the
MEDIA_TUNER_CUSTOMIZE option, something that I think should be inverted and
turned into a menu like most other device driver sections. So rather than
MEDIA_TUNER_CUSTOMIZE, why not just have MEDIA_TUNER be visible to the user,
and if Y, let them select tuners, and if N, no tuners are built.

--
Cheers,
Alistair.

137/1 Warrender Park Road, Edinburgh, UK.
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