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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
ALSA: usb-audio: Replace tasklet with work
The tasklet is an old API that should be deprecated, usually can be
converted to another decent API. In USB-audio driver, a tasklet is
still used in MIDI interface code for handling the output byte
stream. It can be achieved gracefully with a work queued in the
high-prio system workqueue.
This patch replaces the tasklet usage in USB-audio driver with a
simple work.
Link: https://lore.kernel.org/r/20200903104131.21097-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
+7
-6
+7
-6
sound/usb/midi.c
+7
-6
sound/usb/midi.c
···
142
142
unsigned int active_urbs;
143
143
unsigned int drain_urbs;
144
144
int max_transfer; /* size of urb buffer */
145
-
struct tasklet_struct tasklet;
145
+
struct work_struct work;
146
146
unsigned int next_urb;
147
147
spinlock_t buffer_lock;
148
148
···
344
344
spin_unlock_irqrestore(&ep->buffer_lock, flags);
345
345
}
346
346
347
-
static void snd_usbmidi_out_tasklet(struct tasklet_struct *t)
347
+
static void snd_usbmidi_out_work(struct work_struct *work)
348
348
{
349
-
struct snd_usb_midi_out_endpoint *ep = from_tasklet(ep, t, tasklet);
349
+
struct snd_usb_midi_out_endpoint *ep =
350
+
container_of(work, struct snd_usb_midi_out_endpoint, work);
350
351
351
352
snd_usbmidi_do_output(ep);
352
353
}
···
1178
1177
snd_rawmidi_proceed(substream);
1179
1178
return;
1180
1179
}
1181
-
tasklet_schedule(&port->ep->tasklet);
1180
+
queue_work(system_highpri_wq, &port->ep->work);
1182
1181
}
1183
1182
}
1184
1183
···
1441
1440
}
1442
1441
1443
1442
spin_lock_init(&ep->buffer_lock);
1444
-
tasklet_setup(&ep->tasklet, snd_usbmidi_out_tasklet);
1443
+
INIT_WORK(&ep->work, snd_usbmidi_out_work);
1445
1444
init_waitqueue_head(&ep->drain_wait);
1446
1445
1447
1446
for (i = 0; i < 0x10; ++i)
···
1504
1503
for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {
1505
1504
struct snd_usb_midi_endpoint *ep = &umidi->endpoints[i];
1506
1505
if (ep->out)
1507
-
tasklet_kill(&ep->out->tasklet);
1506
+
cancel_work_sync(&ep->out->work);
1508
1507
if (ep->out) {
1509
1508
for (j = 0; j < OUTPUT_URBS; ++j)
1510
1509
usb_kill_urb(ep->out->urbs[j].urb);