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Commit 1365baf7 authored by Oliver Neukum's avatar Oliver Neukum Committed by Greg Kroah-Hartman
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USB: autosuspend for cdc-acm 



Here we go. This patch implements suspend/resume and autosuspend
for the CDC ACM driver.

Signed-off-by: default avatarOliver Neukum <oneukum@suse.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent eedffd12

drivers/usb/class/cdc-acm.c

+77 −15
Original line number Diff line number Diff line
@@ -496,10 +496,19 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp) 
	   otherwise it is scheduled, and with high data rates data can get lost. */

	tty->low_latency = 1;



	if (usb_autopm_get_interface(acm->control)) {

		mutex_unlock(&open_mutex);

		return -EIO;

	}



	mutex_lock(&acm->mutex);

	mutex_unlock(&open_mutex);

	if (acm->used++) {

		usb_autopm_put_interface(acm->control);

		goto done;

        }





	acm->ctrlurb->dev = acm->dev;

	if (usb_submit_urb(acm->ctrlurb, GFP_KERNEL)) {

		dbg("usb_submit_urb(ctrl irq) failed");
@@ -526,14 +535,15 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp) 


done:

err_out:

	mutex_unlock(&open_mutex);

	mutex_unlock(&acm->mutex);

	return rv;



full_bailout:

	usb_kill_urb(acm->ctrlurb);

bail_out:

	usb_autopm_put_interface(acm->control);

	acm->used--;

	mutex_unlock(&open_mutex);

	mutex_unlock(&acm->mutex);

	return -EIO;

}
@@ -570,6 +580,7 @@ static void acm_tty_close(struct tty_struct *tty, struct file *filp) 
			usb_kill_urb(acm->writeurb);

			for (i = 0; i < nr; i++)

				usb_kill_urb(acm->ru[i].urb);

			usb_autopm_put_interface(acm->control);

		} else

			acm_tty_unregister(acm);

	}
@@ -980,6 +991,7 @@ static int acm_probe (struct usb_interface *intf, 
	spin_lock_init(&acm->throttle_lock);

	spin_lock_init(&acm->write_lock);

	spin_lock_init(&acm->read_lock);

	mutex_init(&acm->mutex);

	acm->write_ready = 1;

	acm->rx_endpoint = usb_rcvbulkpipe(usb_dev, epread->bEndpointAddress);
@@ -1096,6 +1108,25 @@ static int acm_probe (struct usb_interface *intf, 
	return -ENOMEM;

}



static void stop_data_traffic(struct acm *acm)

{

	int i;



	tasklet_disable(&acm->urb_task);



	usb_kill_urb(acm->ctrlurb);

	usb_kill_urb(acm->writeurb);

	for (i = 0; i < acm->rx_buflimit; i++)

		usb_kill_urb(acm->ru[i].urb);



	INIT_LIST_HEAD(&acm->filled_read_bufs);

	INIT_LIST_HEAD(&acm->spare_read_bufs);



	tasklet_enable(&acm->urb_task);



	cancel_work_sync(&acm->work);

}



static void acm_disconnect(struct usb_interface *intf)

{

	struct acm *acm = usb_get_intfdata(intf);
@@ -1123,19 +1154,7 @@ static void acm_disconnect(struct usb_interface *intf) 
	usb_set_intfdata(acm->control, NULL);

	usb_set_intfdata(acm->data, NULL);



	tasklet_disable(&acm->urb_task);



	usb_kill_urb(acm->ctrlurb);

	usb_kill_urb(acm->writeurb);

	for (i = 0; i < acm->rx_buflimit; i++)

		usb_kill_urb(acm->ru[i].urb);



	INIT_LIST_HEAD(&acm->filled_read_bufs);

	INIT_LIST_HEAD(&acm->spare_read_bufs);



	tasklet_enable(&acm->urb_task);



	flush_scheduled_work(); /* wait for acm_softint */

	stop_data_traffic(acm);



	acm_write_buffers_free(acm);

	usb_buffer_free(usb_dev, acm->ctrlsize, acm->ctrl_buffer, acm->ctrl_dma);
@@ -1156,6 +1175,46 @@ static void acm_disconnect(struct usb_interface *intf) 
		tty_hangup(acm->tty);

}



static int acm_suspend(struct usb_interface *intf, pm_message_t message)

{

	struct acm *acm = usb_get_intfdata(intf);



	if (acm->susp_count++)

		return 0;

	/*

	we treat opened interfaces differently,

	we must guard against open

	*/

	mutex_lock(&acm->mutex);



	if (acm->used)

		stop_data_traffic(acm);



	mutex_unlock(&acm->mutex);

	return 0;

}



static int acm_resume(struct usb_interface *intf)

{

	struct acm *acm = usb_get_intfdata(intf);

	int rv = 0;



	if (--acm->susp_count)

		return 0;



	mutex_lock(&acm->mutex);

	if (acm->used) {

		rv = usb_submit_urb(acm->ctrlurb, GFP_NOIO);

		if (rv < 0)

		goto err_out;



		tasklet_schedule(&acm->urb_task);

	}



err_out:

	mutex_unlock(&acm->mutex);

	return rv;

}

/*

 * USB driver structure.

 */
@@ -1208,7 +1267,10 @@ static struct usb_driver acm_driver = { 
	.name =		"cdc_acm",

	.probe =	acm_probe,

	.disconnect =	acm_disconnect,

	.suspend =	acm_suspend,

	.resume =	acm_resume,

	.id_table =	acm_ids,

	.supports_autosuspend = 1,

};



/*

drivers/usb/class/cdc-acm.h

+2 −0
Original line number Diff line number Diff line
@@ -107,6 +107,7 @@ struct acm { 
	int write_used;					/* number of non-empty write buffers */

	int write_ready;				/* write urb is not running */

	spinlock_t write_lock;

	struct mutex mutex;

	struct usb_cdc_line_coding line;		/* bits, stop, parity */

	struct work_struct work;			/* work queue entry for line discipline waking up */

	struct tasklet_struct urb_task;                 /* rx processing */
@@ -120,6 +121,7 @@ struct acm { 
	unsigned char throttle;				/* throttled by tty layer */

	unsigned char clocal;				/* termios CLOCAL */

	unsigned int ctrl_caps;				/* control capabilities from the class specific header */

	unsigned int susp_count;			/* number of suspended interfaces */

};



#define CDC_DATA_INTERFACE_TYPE	0x0a