[linux-dvb] [PATCH] Some changes to the Kbuild help
mkrufky at linuxtv.org
Sat Apr 1 22:46:50 CEST 2006
Trent Piepho wrote:
> On Thu, 30 Mar 2006, Michael Krufky wrote:
>>>+ bool "VP-3054 Secondary I2C Bus Support"
>>>+ default y
>>>+ depends on VIDEO_CX88_DVB_MT352 && !VIDEO_CX88_DVB_ALL_FRONTENDS
>>>+ select VIDEO_CX88_VP3054
> You can just use:
> depends on VIDEO_CX88_DVB_MT352
> VIDEO_CX88_DVB_MT352 already pulls in the !VIDEO_CX88_DVB_ALL_FRONTENDS
> for you, as well VIDEO_CX88_DVB and so on.
> This patch solves the problem just fine. As I understand it, what you are
> doing is creating VIDEO_CX88_DVB_VP3054 as a proxy for VIDEO_CX88_VP3054, and
> making it so VIDEO_CX88_VP3054 isn't set directly by the user, but rather via
> VIDEO_CX88_DVB_VP3054. This way VIDEO_CX88_VP3054 doesn't depend _directly_
> on VIDEO_CX88_DVB_MT352, but depends on it via the VIDEO_CX88_DVB_VP3054
> proxy, which kconfig can now display correctly. I don't understand why this
> indirection is necessary, but it works, and that's enough for me.
The indirection is necessary, because VIDEO_CX88_VP3054 cannot both
depend on VIDEO_CX88_DVB_MT352 (which depends on
!VIDEO_CX88_DVB_ALL_FRONTENDS) and be selected by
VIDEO_CX88_DVB_ALL_FRONTENDS at the same time. I don't really know what
that condition is called... "circular dependency paradox" ?
Anyway, I tried the following and it doesn't work because of the
@@ -76,7 +76,7 @@ config VIDEO_CX88_VP3054
tristate "VP-3054 Secondary I2C Bus Support"
- depends on DVB_MT352
+ depends on VIDEO_CX88_DVB_MT352
This adds DVB-T support for cards based on the
Connexant 2388x chip and the MT352 demodulator,
When VIDEO_CX88_DVB_ALL_FRONTENDS is selected, VIDEO_CX88_VP3054 gets
disabled. This is the reason for the indirection.
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