Merge branch 'topic/soundcore-preclaim' into for-linus
* topic/soundcore-preclaim: sound: make OSS device number claiming optional and schedule its removal sound: request char-major-* module aliases for missing OSS devices chrdev: implement __[un]register_chrdev()hifive-unleashed-5.1
Takashi Iwai
commit
3827119e20
|
|
@ -468,3 +468,27 @@ Why: cpu_policy_rwsem has a new cleaner definition making it local to
|
|||
cpufreq core and contained inside cpufreq.c. Other dependent
|
||||
drivers should not use it in order to safely avoid lockdep issues.
|
||||
Who: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
|
||||
|
||||
----------------------------
|
||||
|
||||
What: sound-slot/service-* module aliases and related clutters in
|
||||
sound/sound_core.c
|
||||
When: August 2010
|
||||
Why: OSS sound_core grabs all legacy minors (0-255) of SOUND_MAJOR
|
||||
(14) and requests modules using custom sound-slot/service-*
|
||||
module aliases. The only benefit of doing this is allowing
|
||||
use of custom module aliases which might as well be considered
|
||||
a bug at this point. This preemptive claiming prevents
|
||||
alternative OSS implementations.
|
||||
|
||||
Till the feature is removed, the kernel will be requesting
|
||||
both sound-slot/service-* and the standard char-major-* module
|
||||
aliases and allow turning off the pre-claiming selectively via
|
||||
CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss
|
||||
kernel parameter.
|
||||
|
||||
After the transition phase is complete, both the custom module
|
||||
aliases and switches to disable it will go away. This removal
|
||||
will also allow making ALSA OSS emulation independent of
|
||||
sound_core. The dependency will be broken then too.
|
||||
Who: Tejun Heo <tj@kernel.org>
|
||||
|
|
|
|||
|
|
@ -237,8 +237,10 @@ int alloc_chrdev_region(dev_t *dev, unsigned baseminor, unsigned count,
|
|||
}
|
||||
|
||||
/**
|
||||
* register_chrdev() - Register a major number for character devices.
|
||||
* __register_chrdev() - create and register a cdev occupying a range of minors
|
||||
* @major: major device number or 0 for dynamic allocation
|
||||
* @baseminor: first of the requested range of minor numbers
|
||||
* @count: the number of minor numbers required
|
||||
* @name: name of this range of devices
|
||||
* @fops: file operations associated with this devices
|
||||
*
|
||||
|
|
@ -254,19 +256,17 @@ int alloc_chrdev_region(dev_t *dev, unsigned baseminor, unsigned count,
|
|||
* /dev. It only helps to keep track of the different owners of devices. If
|
||||
* your module name has only one type of devices it's ok to use e.g. the name
|
||||
* of the module here.
|
||||
*
|
||||
* This function registers a range of 256 minor numbers. The first minor number
|
||||
* is 0.
|
||||
*/
|
||||
int register_chrdev(unsigned int major, const char *name,
|
||||
const struct file_operations *fops)
|
||||
int __register_chrdev(unsigned int major, unsigned int baseminor,
|
||||
unsigned int count, const char *name,
|
||||
const struct file_operations *fops)
|
||||
{
|
||||
struct char_device_struct *cd;
|
||||
struct cdev *cdev;
|
||||
char *s;
|
||||
int err = -ENOMEM;
|
||||
|
||||
cd = __register_chrdev_region(major, 0, 256, name);
|
||||
cd = __register_chrdev_region(major, baseminor, count, name);
|
||||
if (IS_ERR(cd))
|
||||
return PTR_ERR(cd);
|
||||
|
||||
|
|
@ -280,7 +280,7 @@ int register_chrdev(unsigned int major, const char *name,
|
|||
for (s = strchr(kobject_name(&cdev->kobj),'/'); s; s = strchr(s, '/'))
|
||||
*s = '!';
|
||||
|
||||
err = cdev_add(cdev, MKDEV(cd->major, 0), 256);
|
||||
err = cdev_add(cdev, MKDEV(cd->major, baseminor), count);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
|
|
@ -290,7 +290,7 @@ int register_chrdev(unsigned int major, const char *name,
|
|||
out:
|
||||
kobject_put(&cdev->kobj);
|
||||
out2:
|
||||
kfree(__unregister_chrdev_region(cd->major, 0, 256));
|
||||
kfree(__unregister_chrdev_region(cd->major, baseminor, count));
|
||||
return err;
|
||||
}
|
||||
|
||||
|
|
@ -316,10 +316,23 @@ void unregister_chrdev_region(dev_t from, unsigned count)
|
|||
}
|
||||
}
|
||||
|
||||
void unregister_chrdev(unsigned int major, const char *name)
|
||||
/**
|
||||
* __unregister_chrdev - unregister and destroy a cdev
|
||||
* @major: major device number
|
||||
* @baseminor: first of the range of minor numbers
|
||||
* @count: the number of minor numbers this cdev is occupying
|
||||
* @name: name of this range of devices
|
||||
*
|
||||
* Unregister and destroy the cdev occupying the region described by
|
||||
* @major, @baseminor and @count. This function undoes what
|
||||
* __register_chrdev() did.
|
||||
*/
|
||||
void __unregister_chrdev(unsigned int major, unsigned int baseminor,
|
||||
unsigned int count, const char *name)
|
||||
{
|
||||
struct char_device_struct *cd;
|
||||
cd = __unregister_chrdev_region(major, 0, 256);
|
||||
|
||||
cd = __unregister_chrdev_region(major, baseminor, count);
|
||||
if (cd && cd->cdev)
|
||||
cdev_del(cd->cdev);
|
||||
kfree(cd);
|
||||
|
|
@ -568,6 +581,6 @@ EXPORT_SYMBOL(cdev_alloc);
|
|||
EXPORT_SYMBOL(cdev_del);
|
||||
EXPORT_SYMBOL(cdev_add);
|
||||
EXPORT_SYMBOL(cdev_index);
|
||||
EXPORT_SYMBOL(register_chrdev);
|
||||
EXPORT_SYMBOL(unregister_chrdev);
|
||||
EXPORT_SYMBOL(__register_chrdev);
|
||||
EXPORT_SYMBOL(__unregister_chrdev);
|
||||
EXPORT_SYMBOL(directly_mappable_cdev_bdi);
|
||||
|
|
|
|||
|
|
@ -1998,12 +1998,25 @@ extern void bd_release_from_disk(struct block_device *, struct gendisk *);
|
|||
#define CHRDEV_MAJOR_HASH_SIZE 255
|
||||
extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);
|
||||
extern int register_chrdev_region(dev_t, unsigned, const char *);
|
||||
extern int register_chrdev(unsigned int, const char *,
|
||||
const struct file_operations *);
|
||||
extern void unregister_chrdev(unsigned int, const char *);
|
||||
extern int __register_chrdev(unsigned int major, unsigned int baseminor,
|
||||
unsigned int count, const char *name,
|
||||
const struct file_operations *fops);
|
||||
extern void __unregister_chrdev(unsigned int major, unsigned int baseminor,
|
||||
unsigned int count, const char *name);
|
||||
extern void unregister_chrdev_region(dev_t, unsigned);
|
||||
extern void chrdev_show(struct seq_file *,off_t);
|
||||
|
||||
static inline int register_chrdev(unsigned int major, const char *name,
|
||||
const struct file_operations *fops)
|
||||
{
|
||||
return __register_chrdev(major, 0, 256, name, fops);
|
||||
}
|
||||
|
||||
static inline void unregister_chrdev(unsigned int major, const char *name)
|
||||
{
|
||||
__unregister_chrdev(major, 0, 256, name);
|
||||
}
|
||||
|
||||
/* fs/block_dev.c */
|
||||
#define BDEVNAME_SIZE 32 /* Largest string for a blockdev identifier */
|
||||
#define BDEVT_SIZE 10 /* Largest string for MAJ:MIN for blkdev */
|
||||
|
|
|
|||
|
|
@ -32,6 +32,34 @@ config SOUND_OSS_CORE
|
|||
bool
|
||||
default n
|
||||
|
||||
config SOUND_OSS_CORE_PRECLAIM
|
||||
bool "Preclaim OSS device numbers"
|
||||
depends on SOUND_OSS_CORE
|
||||
default y
|
||||
help
|
||||
With this option enabled, the kernel will claim all OSS device
|
||||
numbers if any OSS support (native or emulation) is enabled
|
||||
whether the respective module is loaded or not and try to load the
|
||||
appropriate module using sound-slot/service-* and char-major-*
|
||||
module aliases when one of the device numbers is opened. With
|
||||
this option disabled, kernel will only claim actually in-use
|
||||
device numbers and opening a missing device will generate only the
|
||||
standard char-major-* aliases.
|
||||
|
||||
The only visible difference is use of additional module aliases
|
||||
and whether OSS sound devices appear multiple times in
|
||||
/proc/devices. sound-slot/service-* module aliases are scheduled
|
||||
to be removed (ie. PRECLAIM won't be available) and this option is
|
||||
to make the transition easier. This option can be overridden
|
||||
during boot using the kernel parameter soundcore.preclaim_oss.
|
||||
|
||||
Disabling this allows alternative OSS implementations.
|
||||
|
||||
Please read Documentation/feature-removal-schedule.txt for
|
||||
details.
|
||||
|
||||
If unusre, say Y.
|
||||
|
||||
source "sound/oss/dmasound/Kconfig"
|
||||
|
||||
if !M68K
|
||||
|
|
|
|||
|
|
@ -127,6 +127,46 @@ extern int msnd_classic_init(void);
|
|||
extern int msnd_pinnacle_init(void);
|
||||
#endif
|
||||
|
||||
/*
|
||||
* By default, OSS sound_core claims full legacy minor range (0-255)
|
||||
* of SOUND_MAJOR to trap open attempts to any sound minor and
|
||||
* requests modules using custom sound-slot/service-* module aliases.
|
||||
* The only benefit of doing this is allowing use of custom module
|
||||
* aliases instead of the standard char-major-* ones. This behavior
|
||||
* prevents alternative OSS implementation and is scheduled to be
|
||||
* removed.
|
||||
*
|
||||
* CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss kernel
|
||||
* parameter are added to allow distros and developers to try and
|
||||
* switch to alternative implementations without needing to rebuild
|
||||
* the kernel in the meantime. If preclaim_oss is non-zero, the
|
||||
* kernel will behave the same as before. All SOUND_MAJOR minors are
|
||||
* preclaimed and the custom module aliases along with standard chrdev
|
||||
* ones are emitted if a missing device is opened. If preclaim_oss is
|
||||
* zero, sound_core only grabs what's actually in use and for missing
|
||||
* devices only the standard chrdev aliases are requested.
|
||||
*
|
||||
* All these clutters are scheduled to be removed along with
|
||||
* sound-slot/service-* module aliases. Please take a look at
|
||||
* feature-removal-schedule.txt for details.
|
||||
*/
|
||||
#ifdef CONFIG_SOUND_OSS_CORE_PRECLAIM
|
||||
static int preclaim_oss = 1;
|
||||
#else
|
||||
static int preclaim_oss = 0;
|
||||
#endif
|
||||
|
||||
module_param(preclaim_oss, int, 0444);
|
||||
|
||||
static int soundcore_open(struct inode *, struct file *);
|
||||
|
||||
static const struct file_operations soundcore_fops =
|
||||
{
|
||||
/* We must have an owner or the module locking fails */
|
||||
.owner = THIS_MODULE,
|
||||
.open = soundcore_open,
|
||||
};
|
||||
|
||||
/*
|
||||
* Low level list operator. Scan the ordered list, find a hole and
|
||||
* join into it. Called with the lock asserted
|
||||
|
|
@ -219,8 +259,9 @@ static int sound_insert_unit(struct sound_unit **list, const struct file_operati
|
|||
|
||||
if (!s)
|
||||
return -ENOMEM;
|
||||
|
||||
|
||||
spin_lock(&sound_loader_lock);
|
||||
retry:
|
||||
r = __sound_insert_unit(s, list, fops, index, low, top);
|
||||
spin_unlock(&sound_loader_lock);
|
||||
|
||||
|
|
@ -231,11 +272,31 @@ static int sound_insert_unit(struct sound_unit **list, const struct file_operati
|
|||
else
|
||||
sprintf(s->name, "sound/%s%d", name, r / SOUND_STEP);
|
||||
|
||||
if (!preclaim_oss) {
|
||||
/*
|
||||
* Something else might have grabbed the minor. If
|
||||
* first free slot is requested, rescan with @low set
|
||||
* to the next unit; otherwise, -EBUSY.
|
||||
*/
|
||||
r = __register_chrdev(SOUND_MAJOR, s->unit_minor, 1, s->name,
|
||||
&soundcore_fops);
|
||||
if (r < 0) {
|
||||
spin_lock(&sound_loader_lock);
|
||||
__sound_remove_unit(list, s->unit_minor);
|
||||
if (index < 0) {
|
||||
low = s->unit_minor + SOUND_STEP;
|
||||
goto retry;
|
||||
}
|
||||
spin_unlock(&sound_loader_lock);
|
||||
return -EBUSY;
|
||||
}
|
||||
}
|
||||
|
||||
device_create(sound_class, dev, MKDEV(SOUND_MAJOR, s->unit_minor),
|
||||
NULL, s->name+6);
|
||||
return r;
|
||||
return s->unit_minor;
|
||||
|
||||
fail:
|
||||
fail:
|
||||
kfree(s);
|
||||
return r;
|
||||
}
|
||||
|
|
@ -254,6 +315,9 @@ static void sound_remove_unit(struct sound_unit **list, int unit)
|
|||
p = __sound_remove_unit(list, unit);
|
||||
spin_unlock(&sound_loader_lock);
|
||||
if (p) {
|
||||
if (!preclaim_oss)
|
||||
__unregister_chrdev(SOUND_MAJOR, p->unit_minor, 1,
|
||||
p->name);
|
||||
device_destroy(sound_class, MKDEV(SOUND_MAJOR, p->unit_minor));
|
||||
kfree(p);
|
||||
}
|
||||
|
|
@ -491,19 +555,6 @@ void unregister_sound_dsp(int unit)
|
|||
|
||||
EXPORT_SYMBOL(unregister_sound_dsp);
|
||||
|
||||
/*
|
||||
* Now our file operations
|
||||
*/
|
||||
|
||||
static int soundcore_open(struct inode *, struct file *);
|
||||
|
||||
static const struct file_operations soundcore_fops=
|
||||
{
|
||||
/* We must have an owner or the module locking fails */
|
||||
.owner = THIS_MODULE,
|
||||
.open = soundcore_open,
|
||||
};
|
||||
|
||||
static struct sound_unit *__look_for_unit(int chain, int unit)
|
||||
{
|
||||
struct sound_unit *s;
|
||||
|
|
@ -539,8 +590,9 @@ static int soundcore_open(struct inode *inode, struct file *file)
|
|||
s = __look_for_unit(chain, unit);
|
||||
if (s)
|
||||
new_fops = fops_get(s->unit_fops);
|
||||
if (!new_fops) {
|
||||
if (preclaim_oss && !new_fops) {
|
||||
spin_unlock(&sound_loader_lock);
|
||||
|
||||
/*
|
||||
* Please, don't change this order or code.
|
||||
* For ALSA slot means soundcard and OSS emulation code
|
||||
|
|
@ -550,6 +602,17 @@ static int soundcore_open(struct inode *inode, struct file *file)
|
|||
*/
|
||||
request_module("sound-slot-%i", unit>>4);
|
||||
request_module("sound-service-%i-%i", unit>>4, chain);
|
||||
|
||||
/*
|
||||
* sound-slot/service-* module aliases are scheduled
|
||||
* for removal in favor of the standard char-major-*
|
||||
* module aliases. For the time being, generate both
|
||||
* the legacy and standard module aliases to ease
|
||||
* transition.
|
||||
*/
|
||||
if (request_module("char-major-%d-%d", SOUND_MAJOR, unit) > 0)
|
||||
request_module("char-major-%d", SOUND_MAJOR);
|
||||
|
||||
spin_lock(&sound_loader_lock);
|
||||
s = __look_for_unit(chain, unit);
|
||||
if (s)
|
||||
|
|
@ -593,7 +656,8 @@ static void cleanup_oss_soundcore(void)
|
|||
|
||||
static int __init init_oss_soundcore(void)
|
||||
{
|
||||
if (register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops)==-1) {
|
||||
if (preclaim_oss &&
|
||||
register_chrdev(SOUND_MAJOR, "sound", &soundcore_fops) == -1) {
|
||||
printk(KERN_ERR "soundcore: sound device already in use.\n");
|
||||
return -EBUSY;
|
||||
}
|
||||
|
|
|
|||
Loading…
Reference in New Issue