Re: [patch] video: build fix for drivers/media/video/pvrusb2/

From: Mike Isely
Date: Tue May 13 2008 - 11:56:31 EST


On Tue, 13 May 2008, Mauro Carvalho Chehab wrote:

> On Tue, 13 May 2008 00:03:02 -0400
> "Michael Krufky" <mkrufky@xxxxxxxxxxx> wrote:
>
> >
> > That sounds like it would be OK, although something like this would
> > probably be better:
> >
> > config VIDEO_PVRUSB2
> > tristate "Hauppauge WinTV-PVR USB2 support"
> > - depends on VIDEO_V4L2 && I2C
> > + depends on VIDEO_V4L2 && I2C && (DVB_CORE if VIDEO_PVRUSB2_DVB)
> > select FW_LOADER
> > select MEDIA_TUNER
> > select VIDEO_TVEEPROM
>
> This doesn't look to be a good idea, since VIDEO_PVRUSB2_DVB depends on
> VIDEO_PVRUSB2. So, you'll create a circular dependency. The syntax I've
> proposed seems cleaner. Of course, it needs to be tested. IMO, all hybrid
> devices should be dependent of VIDEO_MEDIA. This will help to avoid this kind
> of issue.
>
> > I don't know if that syntax works for "depends on" , but it does work
> > for select.
> >
> > if "depends on FOO if BAR" doesnt work, would adding "select DVB_CORE
> > if VIDEO_PVRUSB2_DVB" solve the problem?
>
> Also, this leads into a circular reference.

Mauro:

Where is the loop that results in a circular reference? No part of V4L
or DVB depends (or otherwise has any reliance) on VIDEO_PVRUSB2. All
Mike Krufky is trying to set up is that VIDEO_PVRUSB2 should only depend
on DVB_CORE if the DVB part of the driver (i.e. VIDEO_PVRUSB2_DVB) has
been enabled. Without VIDEO_PVRUSB2_DVB selected, then DVB_CORE is not
required by the driver.

I've been quiet about this issue because I'm not a kconfig expert, but
you've lost me with this conclusion.

-Mike


--

Mike Isely
isely @ pobox (dot) com
PGP: 03 54 43 4D 75 E5 CC 92 71 16 01 E2 B5 F5 C1 E8
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