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Commit 17d80d56 authored by Oliver Neukum's avatar Oliver Neukum Committed by Greg Kroah-Hartman
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USB: autosuspend for cdc-wdm 



this patch implements

- suspend/resume
- aggressive autosuspend for the cdc-wdm driver
- pre/post_reset

Signed-off-by: default avatarOliver Neukum <oneukum@suse.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 11ea859d

drivers/usb/class/cdc-wdm.c

+101 −6
Original line number Diff line number Diff line
@@ -88,6 +88,7 @@ struct wdm_device { 
	dma_addr_t		ihandle;

	struct mutex		wlock;

	struct mutex		rlock;

	struct mutex		plock;

	wait_queue_head_t	wait;

	struct work_struct	rxwork;

	int			werr;
@@ -248,6 +249,7 @@ exit: 


static void kill_urbs(struct wdm_device *desc)

{

	/* the order here is essential */

	usb_kill_urb(desc->command);

	usb_kill_urb(desc->validity);

	usb_kill_urb(desc->response);
@@ -300,6 +302,9 @@ static ssize_t wdm_write 
	if (r)

		goto outnl;



	r = usb_autopm_get_interface(desc->intf);

	if (r < 0)

		goto outnp;

	r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,

							   &desc->flags));

	if (r < 0)
@@ -354,6 +359,8 @@ static ssize_t wdm_write 
			req->wIndex);

	}

out:

	usb_autopm_put_interface(desc->intf);

outnp:

	mutex_unlock(&desc->wlock);

outnl:

	return rv < 0 ? rv : count;
@@ -378,6 +385,11 @@ retry: 
		rv = wait_event_interruptible(desc->wait,

					      test_bit(WDM_READ, &desc->flags));



		if (test_bit(WDM_DISCONNECTING, &desc->flags)) {

			rv = -ENODEV;

			goto err;

		}

		usb_mark_last_busy(interface_to_usbdev(desc->intf));

		if (rv < 0) {

			rv = -ERESTARTSYS;

			goto err;
@@ -485,18 +497,28 @@ static int wdm_open(struct inode *inode, struct file *file) 
	if (test_bit(WDM_DISCONNECTING, &desc->flags))

		goto out;



	desc->count++;

	;

	file->private_data = desc;



	rv = usb_submit_urb(desc->validity, GFP_KERNEL);

	rv = usb_autopm_get_interface(desc->intf);

	if (rv < 0) {

		err("Error autopm - %d", rv);

		goto out;

	}

	intf->needs_remote_wakeup = 1;



	mutex_lock(&desc->plock);

	if (!desc->count++) {

		rv = usb_submit_urb(desc->validity, GFP_KERNEL);

		if (rv < 0) {

			desc->count--;

			err("Error submitting int urb - %d", rv);

		goto out;

		}

	} else {

		rv = 0;



	}

	mutex_unlock(&desc->plock);

	usb_autopm_put_interface(desc->intf);

out:

	mutex_unlock(&wdm_mutex);

	return rv;
@@ -507,10 +529,15 @@ static int wdm_release(struct inode *inode, struct file *file) 
	struct wdm_device *desc = file->private_data;



	mutex_lock(&wdm_mutex);

	mutex_lock(&desc->plock);

	desc->count--;

	mutex_unlock(&desc->plock);



	if (!desc->count) {

		dev_dbg(&desc->intf->dev, "wdm_release: cleanup");

		kill_urbs(desc);

		if (!test_bit(WDM_DISCONNECTING, &desc->flags))

			desc->intf->needs_remote_wakeup = 0;

	}

	mutex_unlock(&wdm_mutex);

	return 0;
@@ -602,6 +629,7 @@ next_desc: 
		goto out;

	mutex_init(&desc->wlock);

	mutex_init(&desc->rlock);

	mutex_init(&desc->plock);

	spin_lock_init(&desc->iuspin);

	init_waitqueue_head(&desc->wait);

	desc->wMaxCommand = maxcom;
@@ -703,6 +731,7 @@ static void wdm_disconnect(struct usb_interface *intf) 
	spin_lock_irqsave(&desc->iuspin, flags);

	set_bit(WDM_DISCONNECTING, &desc->flags);

	set_bit(WDM_READ, &desc->flags);

	/* to terminate pending flushes */

	clear_bit(WDM_IN_USE, &desc->flags);

	spin_unlock_irqrestore(&desc->iuspin, flags);

	cancel_work_sync(&desc->rxwork);
@@ -713,11 +742,77 @@ static void wdm_disconnect(struct usb_interface *intf) 
	mutex_unlock(&wdm_mutex);

}



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

{

	struct wdm_device *desc = usb_get_intfdata(intf);

	int rv = 0;



	dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);



	mutex_lock(&desc->plock);

	if (interface_to_usbdev(desc->intf)->auto_pm && test_bit(WDM_IN_USE, &desc->flags)) {

		rv = -EBUSY;

	} else {

		cancel_work_sync(&desc->rxwork);

		kill_urbs(desc);

	}

	mutex_unlock(&desc->plock);



	return rv;

}



static int recover_from_urb_loss(struct wdm_device *desc)

{

	int rv = 0;



	if (desc->count) {

		rv = usb_submit_urb(desc->validity, GFP_NOIO);

		if (rv < 0)

			err("Error resume submitting int urb - %d", rv);

	}

	return rv;

}

static int wdm_resume(struct usb_interface *intf)

{

	struct wdm_device *desc = usb_get_intfdata(intf);

	int rv;



	dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);

	mutex_lock(&desc->plock);

	rv = recover_from_urb_loss(desc);

	mutex_unlock(&desc->plock);

	return rv;

}



static int wdm_pre_reset(struct usb_interface *intf)

{

	struct wdm_device *desc = usb_get_intfdata(intf);



	mutex_lock(&desc->plock);

	return 0;

}



static int wdm_post_reset(struct usb_interface *intf)

{

	struct wdm_device *desc = usb_get_intfdata(intf);

	int rv;



	rv = recover_from_urb_loss(desc);

	mutex_unlock(&desc->plock);

	return 0;

}



static struct usb_driver wdm_driver = {

	.name =		"cdc_wdm",

	.probe =	wdm_probe,

	.disconnect =	wdm_disconnect,

	.suspend =	wdm_suspend,

	.resume =	wdm_resume,

	.reset_resume =	wdm_resume,

	.pre_reset =	wdm_pre_reset,

	.post_reset =	wdm_post_reset,

	.id_table =	wdm_ids,

	.supports_autosuspend = 1,

};



/* --- low level module stuff --- */