Sucky dependencies found in video saa7134 rc

Sucky dependencies found in video saa7134 rc

[Steven Rostedt]

Running randconfigs with ktest seems to find this crap all over. It's
not just saa7134, it happens else where too, but this is the one that
I'm currently looking at.

I'm also not blaming the saa7134 driver, but I think we need to find a
way to fix Kconfig to handle this. Maybe it is in the works. I don't
know.

Here's the issue:

1) in the Makefile in drivers/media/video/saa7134/ we have:

aa7134-y :=	saa7134-cards.o saa7134-core.o saa7134-i2c.o
saa7134-y +=	saa7134-ts.o saa7134-tvaudio.o saa7134-vbi.o
saa7134-y +=	saa7134-video.o
saa7134-$(CONFIG_VIDEO_SAA7134_RC) += saa7134-input.o

2) in the Kconfig of that directory:

config VIDEO_SAA7134_RC
	bool "Philips SAA7134 Remote Controller support"
	depends on RC_CORE
	depends on VIDEO_SAA7134
	default y

3) in the Makefile of drivers/media/rc

obj-$(CONFIG_RC_CORE) += rc-core.o

4) in the Kconfig of that directory:

menuconfig RC_CORE
	tristate "Remote Controller adapters"
	depends on INPUT
	default INPUT

And finally in the .config produced by randconfig:

CONFIG_RC_CORE=m
CONFIG_VIDEO_SAA7134=y
CONFIG_VIDEO_SAA7134_RC=y

Thus, RC_CORE is a module and the SAA7134 input file is built in, which
gives me the following error:

drivers/built-in.o: In function `saa7134_input_init1':
/home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:737: undefined reference to `rc_allocate_device'
/home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:780: undefined reference to `rc_register_device'
/home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:787: undefined reference to `rc_free_device'
drivers/built-in.o: In function `saa7134_input_fini':
/home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:799: undefined reference to `rc_unregister_device'
drivers/built-in.o: In function `ir_raw_decode_timer_end':
/home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:400: undefined reference to `ir_raw_event_handle'
drivers/built-in.o: In function `build_key':
/home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:93: undefined reference to `rc_keydown_notimeout'
/home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:101: undefined reference to `rc_keydown_notimeout'
/home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:102: undefined reference to `rc_keyup'
drivers/built-in.o: In function `saa7134_raw_decode_irq':
/home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:920: undefined reference to `ir_raw_event_store_edge'
make[1]: *** [.tmp_vmlinux1] Error 1

I know this is just a randconfig and I doubt that people will actually
run into this problem, but randconfig should always produce a kernel
that can compile, and preferably boot ;)

I think the issue here is that we should never allowed that SAA7134_RC
be set to 'y' when RC_CORE is 'm'. I need to look at the kconfig code
and see if there's a way to prevent that 'y' if its dependencies have
'm'.

Hmm, but that may not work either :( This may be a Makefile issue, as
that 'y' is not really a builtin to the kernel but a builtin to a module
that may or may not be built into the kernel. Which makes this
dependency agnostic to the Kconfigs. God what a horrible tangled web we
weave!

-- Steve

Re: Sucky dependencies found in video saa7134 rc

[Mauro Carvalho Chehab]

Em 10-03-2011 14:37, Steven Rostedt escreveu:
> Running randconfigs with ktest seems to find this crap all over. It's
> not just saa7134, it happens else where too, but this is the one that
> I'm currently looking at.
> 
> I'm also not blaming the saa7134 driver, but I think we need to find a
> way to fix Kconfig to handle this. Maybe it is in the works. I don't
> know.
> 
> Here's the issue:
> 
> 1) in the Makefile in drivers/media/video/saa7134/ we have:
> 
> aa7134-y :=	saa7134-cards.o saa7134-core.o saa7134-i2c.o
> saa7134-y +=	saa7134-ts.o saa7134-tvaudio.o saa7134-vbi.o
> saa7134-y +=	saa7134-video.o
> saa7134-$(CONFIG_VIDEO_SAA7134_RC) += saa7134-input.o
> 
> 2) in the Kconfig of that directory:
> 
> config VIDEO_SAA7134_RC
> 	bool "Philips SAA7134 Remote Controller support"
> 	depends on RC_CORE
> 	depends on VIDEO_SAA7134
> 	default y
> 
> 3) in the Makefile of drivers/media/rc
> 
> obj-$(CONFIG_RC_CORE) += rc-core.o
> 
> 4) in the Kconfig of that directory:
> 
> menuconfig RC_CORE
> 	tristate "Remote Controller adapters"
> 	depends on INPUT
> 	default INPUT
> 
> And finally in the .config produced by randconfig:
> 
> CONFIG_RC_CORE=m
> CONFIG_VIDEO_SAA7134=y
> CONFIG_VIDEO_SAA7134_RC=y
> 
> Thus, RC_CORE is a module and the SAA7134 input file is built in, which
> gives me the following error:
> 
> drivers/built-in.o: In function `saa7134_input_init1':
> /home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:737: undefined reference to `rc_allocate_device'
> /home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:780: undefined reference to `rc_register_device'
> /home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:787: undefined reference to `rc_free_device'
> drivers/built-in.o: In function `saa7134_input_fini':
> /home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:799: undefined reference to `rc_unregister_device'
> drivers/built-in.o: In function `ir_raw_decode_timer_end':
> /home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:400: undefined reference to `ir_raw_event_handle'
> drivers/built-in.o: In function `build_key':
> /home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:93: undefined reference to `rc_keydown_notimeout'
> /home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:101: undefined reference to `rc_keydown_notimeout'
> /home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:102: undefined reference to `rc_keyup'
> drivers/built-in.o: In function `saa7134_raw_decode_irq':
> /home/rostedt/work/autotest/nobackup/linux-test.git/drivers/media/video/saa7134/saa7134-input.c:920: undefined reference to `ir_raw_event_store_edge'
> make[1]: *** [.tmp_vmlinux1] Error 1
> 
> I know this is just a randconfig and I doubt that people will actually
> run into this problem, but randconfig should always produce a kernel
> that can compile, and preferably boot ;)
> 
> I think the issue here is that we should never allowed that SAA7134_RC
> be set to 'y' when RC_CORE is 'm'. I need to look at the kconfig code
> and see if there's a way to prevent that 'y' if its dependencies have
> 'm'.
> 
> Hmm, but that may not work either :( This may be a Makefile issue, as
> that 'y' is not really a builtin to the kernel but a builtin to a module
> that may or may not be built into the kernel. Which makes this
> dependency agnostic to the Kconfigs. God what a horrible tangled web we
> weave!

One solution would be to convert CONFIG_VIDEO_SAA7134_RC into a module,
and change its Kconfig item to tri-state. This way, everything should work
properly.

It is not that hard to convert it to be a module. Like the approach it
was taken for saa7134-alsa and saa7134-dvb, but this would require to move
the IR init code from saa7134 into saa7134-rc, as the -rc module will be
initialized late, and asynchronous.

Unfortunately, I don't have any time soon for doing that. Perhaps an easier
way would be to disable CONFIG_VIDEO_SAA7134_RC if RC_CORE=m and SAA7134=y.

Cheers,
Mauro

[PATCH] saa7134: Fix strange kconfig dependency on RC_CORE

[Steven Rostedt]

As the code in saa7134-input is not a module, but the config for it is
set as a boolean instead of a tristate, this causes a strange dependency
on RC_CORE.

VIDEO_SAA7134_RC (which determines if saa7134-input.o is built) depends
on RC_CORE and VIDEO_SAA7134. If VIDEO_SAA7134 is compiled as 'y' but
RC_CORE is compiled as 'm' VIDEO_SAA7134_RC can still be set to 'y'
which causes undefined symbols that it needs from RC_CORE.

The simplest solution is to not allow VIDEO_SAA7134_RC be enabled if
RC_CORE compiled as a module (m) and VIDEO_SA7134 is compiled into the
kernel (y).

Suggested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Michal Marek <mmarek@suse.cz>
Cc: linux-kbuild <linux-kbuild@vger.kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

---
 drivers/media/video/saa7134/Kconfig |    1 +
 1 file changed, 1 insertion(+)

Index: linux-test.git/drivers/media/video/saa7134/Kconfig
===================================================================
--- linux-test.git.orig/drivers/media/video/saa7134/Kconfig	2011-03-07 22:01:13.046263327 -0500
+++ linux-test.git/drivers/media/video/saa7134/Kconfig	2011-03-10 16:18:26.426709736 -0500
@@ -28,6 +28,7 @@ config VIDEO_SAA7134_RC
 	bool "Philips SAA7134 Remote Controller support"
 	depends on RC_CORE
 	depends on VIDEO_SAA7134
+	depends on !(RC_CORE=m && VIDEO_SAA7134=y)
 	default y
 	---help---
 	  Enables Remote Controller support on saa7134 driver.