[PATCH v5] um/drivers: fix hostaudio build errors

From: Randy Dunlap
Date: Wed Aug 02 2023 - 01:15:15 EST

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

Set CONFIG_SOUND=m in ARCH=um defconfig files to maintain the
status quo of the default configs.

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@xxxxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: lore.kernel.org/r/202307141416.vxuRVpFv-lkp@xxxxxxxxx
Cc: Richard Weinberger <richard@xxxxxx>
Cc: Anton Ivanov <anton.ivanov@xxxxxxxxxxxxxxxxxx>
Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
Cc: linux-um@xxxxxxxxxxxxxxxxxxx
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Takashi Iwai <tiwai@xxxxxxx>
Cc: Jaroslav Kysela <perex@xxxxxxxx>
Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Cc: Nicolas Schier <nicolas@xxxxxxxxx>
Cc: linux-kbuild@xxxxxxxxxxxxxxx
Cc: alsa-devel@xxxxxxxxxxxxxxxx
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:
v5: update ARCH=um defconfig files (Masahiro)

arch/um/configs/i386_defconfig | 1 +
arch/um/configs/x86_64_defconfig | 1 +
arch/um/drivers/Kconfig | 16 +++-------------
arch/um/drivers/Makefile | 2 +-
sound/Kconfig | 2 +-
5 files changed, 7 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
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
- bool
- default UML_SOUND
- tristate
- default UML_SOUND

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
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
diff -- a/arch/um/configs/i386_defconfig b/arch/um/configs/i386_defconfig
--- a/arch/um/configs/i386_defconfig
+++ b/arch/um/configs/i386_defconfig
@@ -34,6 +34,7 @@ CONFIG_TTY_CHAN=y
diff -- a/arch/um/configs/x86_64_defconfig b/arch/um/configs/x86_64_defconfig
--- a/arch/um/configs/x86_64_defconfig
+++ b/arch/um/configs/x86_64_defconfig
@@ -32,6 +32,7 @@ CONFIG_TTY_CHAN=y