Commit c7d9efdf authored by Takashi Iwai's avatar Takashi Iwai
Browse files

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: default avatarTakashi Iwai <tiwai@suse.de>
parent bf083595

sound/usb/midi.c

+7 −6
Original line number Diff line number Diff line
@@ -142,7 +142,7 @@ struct snd_usb_midi_out_endpoint { 
	unsigned int active_urbs;

	unsigned int drain_urbs;

	int max_transfer;		/* size of urb buffer */

	struct tasklet_struct tasklet;

	struct work_struct work;

	unsigned int next_urb;

	spinlock_t buffer_lock;
@@ -344,9 +344,10 @@ static void snd_usbmidi_do_output(struct snd_usb_midi_out_endpoint *ep) 
	spin_unlock_irqrestore(&ep->buffer_lock, flags);

}



static void snd_usbmidi_out_tasklet(struct tasklet_struct *t)

static void snd_usbmidi_out_work(struct work_struct *work)

{

	struct snd_usb_midi_out_endpoint *ep = from_tasklet(ep, t, tasklet);

	struct snd_usb_midi_out_endpoint *ep =

		container_of(work, struct snd_usb_midi_out_endpoint, work);



	snd_usbmidi_do_output(ep);

}
@@ -1177,7 +1178,7 @@ static void snd_usbmidi_output_trigger(struct snd_rawmidi_substream *substream, 
			snd_rawmidi_proceed(substream);

			return;

		}

		tasklet_schedule(&port->ep->tasklet);

		queue_work(system_highpri_wq, &port->ep->work);

	}

}
@@ -1440,7 +1441,7 @@ static int snd_usbmidi_out_endpoint_create(struct snd_usb_midi *umidi, 
	}



	spin_lock_init(&ep->buffer_lock);

	tasklet_setup(&ep->tasklet, snd_usbmidi_out_tasklet);

	INIT_WORK(&ep->work, snd_usbmidi_out_work);

	init_waitqueue_head(&ep->drain_wait);



	for (i = 0; i < 0x10; ++i)
@@ -1503,7 +1504,7 @@ void snd_usbmidi_disconnect(struct list_head *p) 
	for (i = 0; i < MIDI_MAX_ENDPOINTS; ++i) {

		struct snd_usb_midi_endpoint *ep = &umidi->endpoints[i];

		if (ep->out)

			tasklet_kill(&ep->out->tasklet);

			cancel_work_sync(&ep->out->work);

		if (ep->out) {

			for (j = 0; j < OUTPUT_URBS; ++j)

				usb_kill_urb(ep->out->urbs[j].urb);

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