[PATCH v4] um/drivers: fix hostaudio build errors

[Randy Dunlap <rdunlap@infradead.org>]

Use "select"s to ensure that the required kconfig symbols are set
as expected.
Drop HOSTAUDIO since it is now equivalent to UML_SOUND.

Allow SOUND with UML regardless of HAS_IOMEM. Otherwise there is a
kconfig warning for unmet dependencies. (This was not an issue when
SOUND was defined in arch/um/drivers/Kconfig. I have done 50 randconfig
builds and didn't find any issues.)

This fixes build errors when CONFIG_SOUND is not set:

ld: arch/um/drivers/hostaudio_kern.o: in function `hostaudio_cleanup_module':
hostaudio_kern.c:(.exit.text+0xa): undefined reference to `unregister_sound_mixer'
ld: hostaudio_kern.c:(.exit.text+0x15): undefined reference to `unregister_sound_dsp'
ld: arch/um/drivers/hostaudio_kern.o: in function `hostaudio_init_module':
hostaudio_kern.c:(.init.text+0x19): undefined reference to `register_sound_dsp'
ld: hostaudio_kern.c:(.init.text+0x31): undefined reference to `register_sound_mixer'
ld: hostaudio_kern.c:(.init.text+0x49): undefined reference to `unregister_sound_dsp'

and this kconfig warning:
WARNING: unmet direct dependencies detected for SOUND

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Fixes: d886e87cb82b ("sound: make OSS sound core optional")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: lore.kernel.org/r/202307141416.vxuRVpFv-lkp@intel.com
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: linux-um@lists.infradead.org
Cc: Tejun Heo <tj@kernel.org>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: linux-kbuild@vger.kernel.org
Cc: alsa-devel@alsa-project.org
---
v2: don't delete the HOSTAUDIO Kconfig entry (Masahiro)
v3: drop HOSTAUDIO and use CONFIG_UML_SOUND for it in Makefile (Takashi);
    add SOUND depends on "|| UML" to HAS_IOMEM
v4: use depends on instead of select for SOUND (Masahiro);
    use Closes: instead of Link:

 arch/um/drivers/Kconfig  |   16 +++-------------
 arch/um/drivers/Makefile |    2 +-
 sound/Kconfig            |    2 +-
 3 files changed, 5 insertions(+), 15 deletions(-)

diff -- a/arch/um/drivers/Kconfig b/arch/um/drivers/Kconfig
--- a/arch/um/drivers/Kconfig
+++ b/arch/um/drivers/Kconfig
@@ -111,24 +111,14 @@ config SSL_CHAN
 
 config UML_SOUND
 	tristate "Sound support"
+	depends on SOUND
+	select SOUND_OSS_CORE
 	help
 	  This option enables UML sound support.  If enabled, it will pull in
-	  soundcore and the UML hostaudio relay, which acts as a intermediary
+	  the UML hostaudio relay, which acts as a intermediary
 	  between the host's dsp and mixer devices and the UML sound system.
 	  It is safe to say 'Y' here.
 
-config SOUND
-	tristate
-	default UML_SOUND
-
-config SOUND_OSS_CORE
-	bool
-	default UML_SOUND
-
-config HOSTAUDIO
-	tristate
-	default UML_SOUND
-
 endmenu
 
 menu "UML Network Devices"
diff -- a/sound/Kconfig b/sound/Kconfig
--- a/sound/Kconfig
+++ b/sound/Kconfig
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 menuconfig SOUND
 	tristate "Sound card support"
-	depends on HAS_IOMEM
+	depends on HAS_IOMEM || UML
 	help
 	  If you have a sound card in your computer, i.e. if it can say more
 	  than an occasional beep, say Y.
diff -- a/arch/um/drivers/Makefile b/arch/um/drivers/Makefile
--- a/arch/um/drivers/Makefile
+++ b/arch/um/drivers/Makefile
@@ -54,7 +54,7 @@ obj-$(CONFIG_UML_NET) += net.o
 obj-$(CONFIG_MCONSOLE) += mconsole.o
 obj-$(CONFIG_MMAPPER) += mmapper_kern.o 
 obj-$(CONFIG_BLK_DEV_UBD) += ubd.o 
-obj-$(CONFIG_HOSTAUDIO) += hostaudio.o
+obj-$(CONFIG_UML_SOUND) += hostaudio.o
 obj-$(CONFIG_NULL_CHAN) += null.o 
 obj-$(CONFIG_PORT_CHAN) += port.o
 obj-$(CONFIG_PTY_CHAN) += pty.o