At a previous commit, concurrent requests for TLV data are maintained exclusively between read requests and write/command requests. TLV callback handlers in each driver has no risk from concurrent access for reference/change.
In current implementation, 'struct snd_card' has a mutex to control concurrent accesses to user-defined element sets. This commit obsoletes it.
Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp --- include/sound/core.h | 2 -- sound/core/control.c | 37 +++++++++++++------------------------ sound/core/init.c | 1 - 3 files changed, 13 insertions(+), 27 deletions(-)
diff --git a/include/sound/core.h b/include/sound/core.h index 55385588eefa..357f36b5ee80 100644 --- a/include/sound/core.h +++ b/include/sound/core.h @@ -118,8 +118,6 @@ struct snd_card { int user_ctl_count; /* count of all user controls */ struct list_head controls; /* all controls for this card */ struct list_head ctl_files; /* active control files */ - struct mutex user_ctl_lock; /* protects user controls against - concurrent access */
struct snd_info_entry *proc_root; /* root for soundcard specific files */ struct snd_info_entry *proc_id; /* the card id */ diff --git a/sound/core/control.c b/sound/core/control.c index 3648fff28138..c1795b42796e 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -1095,9 +1095,7 @@ static int snd_ctl_elem_user_get(struct snd_kcontrol *kcontrol, char *src = ue->elem_data + snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
- mutex_lock(&ue->card->user_ctl_lock); memcpy(&ucontrol->value, src, size); - mutex_unlock(&ue->card->user_ctl_lock); return 0; }
@@ -1110,11 +1108,9 @@ static int snd_ctl_elem_user_put(struct snd_kcontrol *kcontrol, char *dst = ue->elem_data + snd_ctl_get_ioff(kcontrol, &ucontrol->id) * size;
- mutex_lock(&ue->card->user_ctl_lock); change = memcmp(&ucontrol->value, dst, size) != 0; if (change) memcpy(dst, &ucontrol->value, size); - mutex_unlock(&ue->card->user_ctl_lock); return change; }
@@ -1124,44 +1120,37 @@ static int snd_ctl_elem_user_tlv(struct snd_kcontrol *kcontrol, unsigned int __user *tlv) { struct user_element *ue = kcontrol->private_data; - int change = 0; - void *new_data;
if (op_flag == SNDRV_CTL_TLV_OP_WRITE) { + int change; + void *new_data; + if (size > 1024 * 128) /* sane value */ return -EINVAL;
new_data = memdup_user(tlv, size); if (IS_ERR(new_data)) return PTR_ERR(new_data); - mutex_lock(&ue->card->user_ctl_lock); change = ue->tlv_data_size != size; if (!change) change = memcmp(ue->tlv_data, new_data, size); kfree(ue->tlv_data); ue->tlv_data = new_data; ue->tlv_data_size = size; - mutex_unlock(&ue->card->user_ctl_lock); + + return change; } else { - int ret = 0; + if (!ue->tlv_data_size || !ue->tlv_data) + return -ENXIO; + + if (size < ue->tlv_data_size) + return -ENOSPC;
- mutex_lock(&ue->card->user_ctl_lock); - if (!ue->tlv_data_size || !ue->tlv_data) { - ret = -ENXIO; - goto err_unlock; - } - if (size < ue->tlv_data_size) { - ret = -ENOSPC; - goto err_unlock; - } if (copy_to_user(tlv, ue->tlv_data, ue->tlv_data_size)) - ret = -EFAULT; -err_unlock: - mutex_unlock(&ue->card->user_ctl_lock); - if (ret) - return ret; + return -EFAULT; + + return 0; } - return change; }
static int snd_ctl_elem_init_enum_names(struct user_element *ue) diff --git a/sound/core/init.c b/sound/core/init.c index 00f2cbb76e69..f1425f9af703 100644 --- a/sound/core/init.c +++ b/sound/core/init.c @@ -248,7 +248,6 @@ int snd_card_new(struct device *parent, int idx, const char *xid, INIT_LIST_HEAD(&card->devices); init_rwsem(&card->controls_rwsem); rwlock_init(&card->ctl_files_rwlock); - mutex_init(&card->user_ctl_lock); INIT_LIST_HEAD(&card->controls); INIT_LIST_HEAD(&card->ctl_files); spin_lock_init(&card->files_lock);