[PATCH v2 1/5] ALSA: control - introduce snd_ctl_notify_one() helper
Jaroslav Kysela
perex at perex.cz
Mon Feb 15 18:24:14 CET 2021
This helper is required for the following generic LED mute
patch. The helper also simplifies some other functions.
Signed-off-by: Jaroslav Kysela <perex at perex.cz>
---
include/sound/control.h | 4 +--
sound/core/control.c | 68 +++++++++++++++++++++++++++--------------
2 files changed, 47 insertions(+), 25 deletions(-)
diff --git a/include/sound/control.h b/include/sound/control.h
index 77d9fa10812d..22f3d48163ff 100644
--- a/include/sound/control.h
+++ b/include/sound/control.h
@@ -115,6 +115,7 @@ typedef int (*snd_kctl_ioctl_func_t) (struct snd_card * card,
unsigned int cmd, unsigned long arg);
void snd_ctl_notify(struct snd_card * card, unsigned int mask, struct snd_ctl_elem_id * id);
+void snd_ctl_notify_one(struct snd_card * card, unsigned int mask, struct snd_kcontrol * kctl, unsigned int ioff);
struct snd_kcontrol *snd_ctl_new1(const struct snd_kcontrol_new * kcontrolnew, void * private_data);
void snd_ctl_free_one(struct snd_kcontrol * kcontrol);
@@ -123,8 +124,7 @@ int snd_ctl_remove(struct snd_card * card, struct snd_kcontrol * kcontrol);
int snd_ctl_replace(struct snd_card *card, struct snd_kcontrol *kcontrol, bool add_on_replace);
int snd_ctl_remove_id(struct snd_card * card, struct snd_ctl_elem_id *id);
int snd_ctl_rename_id(struct snd_card * card, struct snd_ctl_elem_id *src_id, struct snd_ctl_elem_id *dst_id);
-int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
- int active);
+int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id, int active);
struct snd_kcontrol *snd_ctl_find_numid(struct snd_card * card, unsigned int numid);
struct snd_kcontrol *snd_ctl_find_id(struct snd_card * card, struct snd_ctl_elem_id *id);
diff --git a/sound/core/control.c b/sound/core/control.c
index 5165741a8400..8a5cedb0a4be 100644
--- a/sound/core/control.c
+++ b/sound/core/control.c
@@ -181,6 +181,27 @@ void snd_ctl_notify(struct snd_card *card, unsigned int mask,
}
EXPORT_SYMBOL(snd_ctl_notify);
+/**
+ * snd_ctl_notify_one - Send notification to user-space for a control change
+ * @card: the card to send notification
+ * @mask: the event mask, SNDRV_CTL_EVENT_*
+ * @kctl: the pointer with the control instance
+ * @ioff: the additional offset to the control index
+ *
+ * This function calls snd_ctl_notify() and does additional jobs
+ * like LED state changes.
+ */
+void snd_ctl_notify_one(struct snd_card *card, unsigned int mask,
+ struct snd_kcontrol *kctl, unsigned int ioff)
+{
+ struct snd_ctl_elem_id id = kctl->id;
+
+ id.index += ioff;
+ id.numid += ioff;
+ snd_ctl_notify(card, mask, &id);
+}
+EXPORT_SYMBOL(snd_ctl_notify_one);
+
/**
* snd_ctl_new - create a new control instance with some elements
* @kctl: the pointer to store new control instance
@@ -342,7 +363,6 @@ static int __snd_ctl_add_replace(struct snd_card *card,
{
struct snd_ctl_elem_id id;
unsigned int idx;
- unsigned int count;
struct snd_kcontrol *old;
int err;
@@ -376,10 +396,8 @@ static int __snd_ctl_add_replace(struct snd_card *card,
kcontrol->id.numid = card->last_numid + 1;
card->last_numid += kcontrol->count;
- id = kcontrol->id;
- count = kcontrol->count;
- for (idx = 0; idx < count; idx++, id.index++, id.numid++)
- snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_ADD, &id);
+ for (idx = 0; idx < kcontrol->count; idx++)
+ snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_ADD, kcontrol, idx);
return 0;
}
@@ -462,16 +480,14 @@ EXPORT_SYMBOL(snd_ctl_replace);
*/
int snd_ctl_remove(struct snd_card *card, struct snd_kcontrol *kcontrol)
{
- struct snd_ctl_elem_id id;
unsigned int idx;
if (snd_BUG_ON(!card || !kcontrol))
return -EINVAL;
list_del(&kcontrol->list);
card->controls_count -= kcontrol->count;
- id = kcontrol->id;
- for (idx = 0; idx < kcontrol->count; idx++, id.index++, id.numid++)
- snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_REMOVE, &id);
+ for (idx = 0; idx < kcontrol->count; idx++)
+ snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_REMOVE, kcontrol, idx);
snd_ctl_free_one(kcontrol);
return 0;
}
@@ -584,11 +600,13 @@ int snd_ctl_activate_id(struct snd_card *card, struct snd_ctl_elem_id *id,
vd->access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
}
snd_ctl_build_ioff(id, kctl, index_offset);
- ret = 1;
+ downgrade_write(&card->controls_rwsem);
+ snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_INFO, kctl, index_offset);
+ up_read(&card->controls_rwsem);
+ return 1;
+
unlock:
up_write(&card->controls_rwsem);
- if (ret > 0)
- snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_INFO, id);
return ret;
}
EXPORT_SYMBOL_GPL(snd_ctl_activate_id);
@@ -1110,25 +1128,34 @@ static int snd_ctl_elem_write(struct snd_card *card, struct snd_ctl_file *file,
unsigned int index_offset;
int result;
+ down_write(&card->controls_rwsem);
kctl = snd_ctl_find_id(card, &control->id);
- if (kctl == NULL)
+ if (kctl == NULL) {
+ up_write(&card->controls_rwsem);
return -ENOENT;
+ }
index_offset = snd_ctl_get_ioff(kctl, &control->id);
vd = &kctl->vd[index_offset];
if (!(vd->access & SNDRV_CTL_ELEM_ACCESS_WRITE) || kctl->put == NULL ||
(file && vd->owner && vd->owner != file)) {
+ up_write(&card->controls_rwsem);
return -EPERM;
}
snd_ctl_build_ioff(&control->id, kctl, index_offset);
result = kctl->put(kctl, control);
- if (result < 0)
+ if (result < 0) {
+ up_write(&card->controls_rwsem);
return result;
+ }
if (result > 0) {
- struct snd_ctl_elem_id id = control->id;
- snd_ctl_notify(card, SNDRV_CTL_EVENT_MASK_VALUE, &id);
+ downgrade_write(&card->controls_rwsem);
+ snd_ctl_notify_one(card, SNDRV_CTL_EVENT_MASK_VALUE, kctl, index_offset);
+ up_read(&card->controls_rwsem);
+ } else {
+ up_write(&card->controls_rwsem);
}
return 0;
@@ -1150,9 +1177,7 @@ static int snd_ctl_elem_write_user(struct snd_ctl_file *file,
if (result < 0)
goto error;
- down_write(&card->controls_rwsem);
result = snd_ctl_elem_write(card, file, control);
- up_write(&card->controls_rwsem);
if (result < 0)
goto error;
@@ -1301,7 +1326,6 @@ static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
{
struct user_element *ue = kctl->private_data;
unsigned int *container;
- struct snd_ctl_elem_id id;
unsigned int mask = 0;
int i;
int change;
@@ -1333,10 +1357,8 @@ static int replace_user_tlv(struct snd_kcontrol *kctl, unsigned int __user *buf,
ue->tlv_data_size = size;
mask |= SNDRV_CTL_EVENT_MASK_TLV;
- for (i = 0; i < kctl->count; ++i) {
- snd_ctl_build_ioff(&id, kctl, i);
- snd_ctl_notify(ue->card, mask, &id);
- }
+ for (i = 0; i < kctl->count; ++i)
+ snd_ctl_notify_one(ue->card, mask, kctl, i);
return change;
}
--
2.29.2
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