ALSA: mark all struct bus_type as const

Now that the driver core can properly handle constant struct bus_type,
move all of the sound subsystem struct bus_type structures as const,
placing them into read-only memory which can not be modified at runtime.

Note, this fixes a duplicate definition of ac97_bus_type, which somehow
was declared extern in a .h file, and then static as a prototype in a .c
file, and then properly later on in the same .c file.  Amazing that no
compiler warning ever showed up for this.

Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Dawei Li <set_pte_at@outlook.com>
Cc: Yu Liao <liaoyu15@huawei.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: linux-sound@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/2023121945-immersion-budget-d0aa@gregkh
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Greg Kroah-Hartman 2023-12-19 14:34:46 +01:00 committed by Takashi Iwai
parent 64bf8dec54
commit 66e82d2199
5 changed files with 4 additions and 6 deletions

View File

@ -410,7 +410,7 @@ int snd_ac97_pcm_close(struct ac97_pcm *pcm);
int snd_ac97_pcm_double_rate_rules(struct snd_pcm_runtime *runtime);
/* ad hoc AC97 device driver access */
extern struct bus_type ac97_bus_type;
extern const struct bus_type ac97_bus_type;
/* AC97 platform_data adding function */
static inline void snd_ac97_dev_add_pdata(struct snd_ac97 *ac97, void *data)

View File

@ -33,7 +33,7 @@ struct hda_device_id;
/*
* exported bus type
*/
extern struct bus_type snd_hda_bus_type;
extern const struct bus_type snd_hda_bus_type;
/*
* generic arrays

View File

@ -28,8 +28,6 @@ static DEFINE_MUTEX(ac97_controllers_mutex);
static DEFINE_IDR(ac97_adapter_idr);
static LIST_HEAD(ac97_controllers);
static struct bus_type ac97_bus_type;
static inline struct ac97_controller*
to_ac97_controller(struct device *ac97_adapter)
{

View File

@ -75,7 +75,7 @@ int snd_ac97_reset(struct snd_ac97 *ac97, bool try_warm, unsigned int id,
}
EXPORT_SYMBOL_GPL(snd_ac97_reset);
struct bus_type ac97_bus_type = {
const struct bus_type ac97_bus_type = {
.name = "ac97",
};

View File

@ -76,7 +76,7 @@ static int hda_uevent(const struct device *dev, struct kobj_uevent_env *env)
return 0;
}
struct bus_type snd_hda_bus_type = {
const struct bus_type snd_hda_bus_type = {
.name = "hdaudio",
.match = hda_bus_match,
.uevent = hda_uevent,