Subject: Re: linux-next: Tree for May 1 (media/usb/stk1160)

From: Mauro Carvalho Chehab <[email-masked]>
Date: Thu, 02 May 2013 11:52:33 -0300

Em 01-05-2013 14:59, Randy Dunlap escreveu:
> On 05/01/13 01:37, Stephen Rothwell wrote:
>> Hi all,
>>
>> Please do not add any v3.11 destined work to your linux-next included
>> branches until after v3.10-rc1 is released.
>>
>> Changes since 20130430:
>>
>
>
> When CONFIG_SND=m and CONFIG_SND_AC97_CODEC=m and
> CONFIG_VIDEO_STK1160=y
> CONFIG_VIDEO_STK1160_AC97=y
>
> drivers/built-in.o: In function `stk1160_ac97_register':
> (.text+0x122706): undefined reference to `snd_card_create'
> drivers/built-in.o: In function `stk1160_ac97_register':
> (.text+0x1227b2): undefined reference to `snd_ac97_bus'
> drivers/built-in.o: In function `stk1160_ac97_register':
> (.text+0x1227cd): undefined reference to `snd_card_free'
> drivers/built-in.o: In function `stk1160_ac97_register':
> (.text+0x12281b): undefined reference to `snd_ac97_mixer'
> drivers/built-in.o: In function `stk1160_ac97_register':
> (.text+0x122832): undefined reference to `snd_card_register'
> drivers/built-in.o: In function `stk1160_ac97_unregister':
> (.text+0x12285e): undefined reference to `snd_card_free'
>
>
> This kconfig fragment:
> config VIDEO_STK1160_AC97
> 	bool "STK1160 AC97 codec support"
> 	depends on VIDEO_STK1160 && SND
> 	select SND_AC97_CODEC
>
> is unreliable (doesn't do what some people expect) when SND=m and SND_AC97_CODEC=m,
> since VIDEO_STK1160_AC97 is a bool.

Using select is always tricky.

I can see a few possible fixes for it:

1) split the alsa part into a separate module. IMHO, this is cleaner,
but requires a little more work.

2) Use the Kconfig syntax:

	depends on SND || (SND=n)

on a tristate symbol. That behaves like:

	if SND is 'n', it won't depend on SND;
	if SND is 'm', the symbol will be 'm'
	if SND is 'y', the symbol will be 'y'.

However, as as VIDEO_STK1160_AC97 is boolean, this will require
an additional hidden Kconfig. Something like:

config VIDEO_STK1160_COMMON
	tristate "STK1160 USB video capture support"
	depends on VIDEO_DEV && I2C

config VIDEO_STK1160_AC97
	bool "STK1160 AC97 codec support"
	depends on VIDEO_STK1160_COMMON && SND

config VIDEO_STK1160
	tristate
	depends on ((SND || (SND=n) || !VIDEO_STK1160_AC97) && VIDEO_STK1160_COMMON
	default y
	select SND_AC97_CODEC if SND
	select VIDEOBUF2_VMALLOC
	select VIDEO_SAA711X
	select SND_AC97_CODEC

We do already something similar to the above for the mutual dependency
of most media drivers for I2C and V4L2 and/or DVB core.

There's just one small drawback with the above: if SND='m', even if
the user selects VIDEO_STK1160_COMMON='y', VIDEO_STK1160 will be 'm'.

A quick test here with make allyesconfig and then changing SND to m
seemed to produce the right value for CONFIG_VIDEO_STK1160:

Selecting STK1160_AC97:

$ grep -e STK1160 -e SND= .config
CONFIG_VIDEO_STK1160_COMMON=y
CONFIG_VIDEO_STK1160_AC97=y
CONFIG_VIDEO_STK1160=m
CONFIG_SND=m

Unselecting STK1160_AC97:

$ grep -e STK1160 -e SND= .config
CONFIG_VIDEO_STK1160_COMMON=y
# CONFIG_VIDEO_STK1160_AC97 is not set
CONFIG_VIDEO_STK1160=y
CONFIG_SND=m

With a little more work, it could be possible to find a way to
avoid the drawback of saying to the user that the module will be
builtin, but compiling it as a module.

Regards,
Mauro.

-

[media] stk1160: Make stk1160 module if SND is m and audio support is selected

As reported by Randy:

When CONFIG_SND=m and CONFIG_SND_AC97_CODEC=m and
CONFIG_VIDEO_STK1160=y
CONFIG_VIDEO_STK1160_AC97=y

drivers/built-in.o: In function `stk1160_ac97_register':
(.text+0x122706): undefined reference to `snd_card_create'
drivers/built-in.o: In function `stk1160_ac97_register':
(.text+0x1227b2): undefined reference to `snd_ac97_bus'
drivers/built-in.o: In function `stk1160_ac97_register':
(.text+0x1227cd): undefined reference to `snd_card_free'
drivers/built-in.o: In function `stk1160_ac97_register':
(.text+0x12281b): undefined reference to `snd_ac97_mixer'
drivers/built-in.o: In function `stk1160_ac97_register':
(.text+0x122832): undefined reference to `snd_card_register'
drivers/built-in.o: In function `stk1160_ac97_unregister':
(.text+0x12285e): undefined reference to `snd_card_free'

Reported-by: Randy Dunlap <[email-masked]>
Signed-off-by: Mauro Carvalho Chehab <[email-masked]>

diff --git a/drivers/media/usb/stk1160/Kconfig b/drivers/media/usb/stk1160/Kconfig
index 1c3a1ec..2bf6392 100644
--- a/drivers/media/usb/stk1160/Kconfig
+++ b/drivers/media/usb/stk1160/Kconfig
@@ -1,8 +1,6 @@
-config VIDEO_STK1160
+config VIDEO_STK1160_COMMON
  	tristate "STK1160 USB video capture support"
  	depends on VIDEO_DEV && I2C
-	select VIDEOBUF2_VMALLOC
-	select VIDEO_SAA711X
  
  	---help---
  	  This is a video4linux driver for STK1160 based video capture devices.
@@ -12,9 +10,14 @@ config VIDEO_STK1160
  
  config VIDEO_STK1160_AC97
  	bool "STK1160 AC97 codec support"
-	depends on VIDEO_STK1160 && SND
-	select SND_AC97_CODEC
-
+	depends on VIDEO_STK1160_COMMON && SND
  	---help---
  	  Enables AC97 codec support for stk1160 driver.
-.
+
+config VIDEO_STK1160
+	tristate
+	depends on (!VIDEO_STK1160_AC97 || (SND='n') || SND) && VIDEO_STK1160_COMMON
+	default y
+	select VIDEOBUF2_VMALLOC
+	select VIDEO_SAA711X
+	select SND_AC97_CODEC if SND