mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-08-23 09:19:51 +00:00
Code Issues Releases Wiki Activity

ALSA: firewire-tascam: apply small refactoring to handle several type of event for hwdep interface

Browse source 
In later commits, ALSA firewire-tascam driver will allow userspace
applications to receive notifications about changes of device state,
transferred in tx isochronous packet. At present, all of drivers in ALSA
firewire stack have mechanism to notify change of status of packet
streaming, thus it needs to distinguish these two types of notification.

This commit is a preparation for the above.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Sakamoto 2018-11-23 13:13:06 +09:00 committed by Takashi Iwai
parent d716742243
commit afb8e2daa0
1 changed files with 26 additions and 12 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

38
sound/firewire/tascam/tascam-hwdep.c
View file

@ -16,14 +16,30 @@
#include "tascam.h"
static long tscm_hwdep_read_locked(struct snd_tscm *tscm, char __user *buf,
long count, loff_t *offset)
{
struct snd_firewire_event_lock_status event = {
.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS,
};
event.status = (tscm->dev_lock_count > 0);
tscm->dev_lock_changed = false;
count = min_t(long, count, sizeof(event));
spin_unlock_irq(&tscm->lock);
if (copy_to_user(buf, &event, count))
return -EFAULT;
return count;
}
static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
loff_t *offset)
{
struct snd_tscm *tscm = hwdep->private_data;
DEFINE_WAIT(wait);
union snd_firewire_event event = {
.lock_status.type = SNDRV_FIREWIRE_EVENT_LOCK_STATUS,
};
spin_lock_irq(&tscm->lock);
@ -37,15 +53,13 @@ static long hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count,
spin_lock_irq(&tscm->lock);
}
event.lock_status.status = (tscm->dev_lock_count > 0);
tscm->dev_lock_changed = false;
spin_unlock_irq(&tscm->lock);
count = min_t(long, count, sizeof(event.lock_status));
if (copy_to_user(buf, &event, count))
return -EFAULT;
// NOTE: The acquired lock should be released in callee side.
if (tscm->dev_lock_changed) {
count = tscm_hwdep_read_locked(tscm, buf, count, offset);
} else {
spin_unlock_irq(&tscm->lock);
count = 0;
}
return count;
}