Re: [PATCH RESEND] sound: make OSS sound core optional

From: Tejun Heo
Date: Wed Aug 27 2008 - 05:58:38 EST


Takashi Iwai wrote:
>> SOUND_OSS_CORE should be turned on if ALSA OSS emul is turned on or
>> arch-um hostsound is turned on, both of which can be enabled regardless
>> of SOUND_PRIME, no?
>
> Yes, sorry, I didn't cite clearly. I meant only the last line.
> sound/oss/dmasound/Kconfig is included and evaluated outside the block
> "if SOUND_PRIME". Thus, CONFIG_SOUND_OSS_CORE won't be enabled for
> drivers in sound/oss/dmasound.

Ah.. okay, dmasound also requires SOUND_OSS_CORE but not in
SOUND_PRIME. I see.

> My suggestion is to move that line source sound/oss/dmasound/Kconfig
> into the "if SOUND_PRIME" block first, then apply your patch.

That would pull in sound_firmware. Most likely no big deal but
still... How about just adding select SOUND_OSS_CORE to DMASOUND for
now?

Thanks.

Subject: [PATCH] sound: make OSS sound core optional

sound/sound_core.c implements soundcore.ko and contains two parts -
sound_class which is shared by both ALSA and OSS and device
redirection support for OSS. It's always compiled when any sound
support is enabled although it's necessary only when OSS (the actual
one or emulation) is enabled. This is slightly wasteful and as device
redirection always registers character device region for major 14, it
prevents alternative implementation.

This patch introduces a new config SOUND_OSS_CORE which is selected
iff OSS support is actually necessary and build the OSS core part
conditionally.

If OSS is disabled, soundcore merely contains sound_class but leaving
it that way seems to be the simplest approach as otherwise sound_class
should be in ALSA core file if OSS is disabled but should be in
soundcore if OSS is enabled. Also, there's also the user confusion
factor.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
arch/um/Kconfig.char | 4 ++
sound/Kconfig | 5 ++
sound/core/Kconfig | 1
sound/oss/dmasound/Kconfig | 1
sound/sound_core.c | 79 ++++++++++++++++++++++++++++++++++-----------
5 files changed, 71 insertions(+), 19 deletions(-)

Index: work/sound/Kconfig
===================================================================
--- work.orig/sound/Kconfig
+++ work/sound/Kconfig
@@ -28,6 +28,10 @@ menuconfig SOUND

if SOUND

+config SOUND_OSS_CORE
+ bool
+ default n
+
source "sound/oss/dmasound/Kconfig"

if !M68K
@@ -80,6 +84,7 @@ endif # SND

menuconfig SOUND_PRIME
tristate "Open Sound System (DEPRECATED)"
+ select SOUND_OSS_CORE
help
Say 'Y' or 'M' to enable Open Sound System drivers.

Index: work/sound/core/Kconfig
===================================================================
--- work.orig/sound/core/Kconfig
+++ work/sound/core/Kconfig
@@ -38,6 +38,7 @@ config SND_SEQ_DUMMY
will be called snd-seq-dummy.

config SND_OSSEMUL
+ select SOUND_OSS_CORE
bool

config SND_MIXER_OSS
Index: work/sound/sound_core.c
===================================================================
--- work.orig/sound/sound_core.c
+++ work/sound/sound_core.c
@@ -1,5 +1,61 @@
/*
- * Sound core handling. Breaks out sound functions to submodules
+ * Sound core. This file is composed of two parts. sound_class
+ * which is common to both OSS and ALSA and OSS sound core which
+ * is used OSS or emulation of it.
+ */
+
+/*
+ * First, the common part.
+ */
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/err.h>
+
+#ifdef CONFIG_SOUND_OSS_CORE
+static int __init init_oss_soundcore(void);
+static void __exit cleanup_oss_soundcore(void);
+#else
+static inline int init_oss_soundcore(void) { return 0; }
+static inline void cleanup_oss_soundcore(void) { }
+#endif
+
+struct class *sound_class;
+EXPORT_SYMBOL(sound_class);
+
+MODULE_DESCRIPTION("Core sound module");
+MODULE_AUTHOR("Alan Cox");
+MODULE_LICENSE("GPL");
+
+static int __init init_soundcore(void)
+{
+ int rc;
+
+ rc = init_oss_soundcore();
+ if (rc)
+ return rc;
+
+ sound_class = class_create(THIS_MODULE, "sound");
+ if (IS_ERR(sound_class)) {
+ cleanup_oss_soundcore();
+ return PTR_ERR(sound_class);
+ }
+
+ return 0;
+}
+
+static void __exit cleanup_soundcore(void)
+{
+ cleanup_oss_soundcore();
+ class_destroy(sound_class);
+}
+
+module_init(init_soundcore);
+module_exit(cleanup_soundcore);
+
+
+#ifdef CONFIG_SOUND_OSS_CORE
+/*
+ * OSS sound core handling. Breaks out sound functions to submodules
*
* Author: Alan Cox <alan.cox@xxxxxxxxx>
*
@@ -34,21 +90,17 @@
* locking at some point in 2.3.x.
*/

-#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/smp_lock.h>
#include <linux/types.h>
#include <linux/kernel.h>
-#include <linux/fs.h>
#include <linux/sound.h>
#include <linux/major.h>
#include <linux/kmod.h>
-#include <linux/device.h>

#define SOUND_STEP 16

-
struct sound_unit
{
int unit_minor;
@@ -64,9 +116,6 @@ extern int msnd_classic_init(void);
extern int msnd_pinnacle_init(void);
#endif

-struct class *sound_class;
-EXPORT_SYMBOL(sound_class);
-
/*
* Low level list operator. Scan the ordered list, find a hole and
* join into it. Called with the lock asserted
@@ -523,31 +572,23 @@ int soundcore_open(struct inode *inode,
return -ENODEV;
}

-MODULE_DESCRIPTION("Core sound module");
-MODULE_AUTHOR("Alan Cox");
-MODULE_LICENSE("GPL");
MODULE_ALIAS_CHARDEV_MAJOR(SOUND_MAJOR);

-static void __exit cleanup_soundcore(void)
+static void __exit cleanup_oss_soundcore(void)
{
/* We have nothing to really do here - we know the lists must be
empty */
unregister_chrdev(SOUND_MAJOR, "sound");
- class_destroy(sound_class);
}

-static int __init init_soundcore(void)
+static int __init init_oss_soundcore(void)
{
if (register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops)==-1) {
printk(KERN_ERR "soundcore: sound device already in use.\n");
return -EBUSY;
}
- sound_class = class_create(THIS_MODULE, "sound");
- if (IS_ERR(sound_class))
- return PTR_ERR(sound_class);

return 0;
}

-module_init(init_soundcore);
-module_exit(cleanup_soundcore);
+#endif /* CONFIG_SOUND_OSS_CORE */
Index: work/arch/um/Kconfig.char
===================================================================
--- work.orig/arch/um/Kconfig.char
+++ work/arch/um/Kconfig.char
@@ -203,6 +203,10 @@ config SOUND
tristate
default UML_SOUND

+config SOUND_OSS_CORE
+ bool
+ default UML_SOUND
+
config HOSTAUDIO
tristate
default UML_SOUND
Index: work/sound/oss/dmasound/Kconfig
===================================================================
--- work.orig/sound/oss/dmasound/Kconfig
+++ work/sound/oss/dmasound/Kconfig
@@ -42,3 +42,4 @@ config DMASOUND_Q40

config DMASOUND
tristate
+ select SOUND_OSS_CORE
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/