HID: usbhid: base runtime PM on modern API

This patch doesn't alter functionality, but removes a dedicated kernel
thread.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Tested-by: Maulik Mankad <x0082077@ti.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/usbhid/hid-core.c

@@ -67,7 +67,6 @@ MODULE_PARM_DESC(quirks, "Add/modify USB HID quirks by specifying "
  * Input submission and I/O error handler.
  */
 static DEFINE_MUTEX(hid_open_mut);
-static struct workqueue_struct *resumption_waker;
 
 static void hid_io_error(struct hid_device *hid);
 static int hid_submit_out(struct hid_device *hid);
@@ -300,10 +299,19 @@ static int hid_submit_out(struct hid_device *hid)
 	struct hid_report *report;
 	char *raw_report;
 	struct usbhid_device *usbhid = hid->driver_data;
+	int r;
 
 	report = usbhid->out[usbhid->outtail].report;
 	raw_report = usbhid->out[usbhid->outtail].raw_report;
 
+	r = usb_autopm_get_interface_async(usbhid->intf);
+	if (r < 0)
+		return -1;
+
+	/*
+	 * if the device hasn't been woken, we leave the output
+	 * to resume()
+	 */
 	if (!test_bit(HID_REPORTED_IDLE, &usbhid->iofl)) {
 		usbhid->urbout->transfer_buffer_length = ((report->size - 1) >> 3) + 1 + (report->id > 0);
 		usbhid->urbout->dev = hid_to_usb_dev(hid);
@@ -314,16 +322,10 @@ static int hid_submit_out(struct hid_device *hid)
 
 		if (usb_submit_urb(usbhid->urbout, GFP_ATOMIC)) {
 			hid_err(hid, "usb_submit_urb(out) failed\n");
+			usb_autopm_put_interface_async(usbhid->intf);
 			return -1;
 		}
 		usbhid->last_out = jiffies;
-	} else {
-		/*
-		 * queue work to wake up the device.
-		 * as the work queue is freezeable, this is safe
-		 * with respect to STD and STR
-		 */
-		queue_work(resumption_waker, &usbhid->restart_work);
 	}
 
 	return 0;
@@ -334,13 +336,16 @@ static int hid_submit_ctrl(struct hid_device *hid)
 	struct hid_report *report;
 	unsigned char dir;
 	char *raw_report;
-	int len;
+	int len, r;
 	struct usbhid_device *usbhid = hid->driver_data;
 
 	report = usbhid->ctrl[usbhid->ctrltail].report;
 	raw_report = usbhid->ctrl[usbhid->ctrltail].raw_report;
 	dir = usbhid->ctrl[usbhid->ctrltail].dir;
 
+	r = usb_autopm_get_interface_async(usbhid->intf);
+	if (r < 0)
+		return -1;
 	if (!test_bit(HID_REPORTED_IDLE, &usbhid->iofl)) {
 		len = ((report->size - 1) >> 3) + 1 + (report->id > 0);
 		if (dir == USB_DIR_OUT) {
@@ -375,17 +380,11 @@ static int hid_submit_ctrl(struct hid_device *hid)
 			usbhid->cr->wValue, usbhid->cr->wIndex, usbhid->cr->wLength);
 
 		if (usb_submit_urb(usbhid->urbctrl, GFP_ATOMIC)) {
+			usb_autopm_put_interface_async(usbhid->intf);
 			hid_err(hid, "usb_submit_urb(ctrl) failed\n");
 			return -1;
 		}
 		usbhid->last_ctrl = jiffies;
-	} else {
-		/*
-		 * queue work to wake up the device.
-		 * as the work queue is freezeable, this is safe
-		 * with respect to STD and STR
-		 */
-		queue_work(resumption_waker, &usbhid->restart_work);
 	}
 
 	return 0;
@@ -435,6 +434,7 @@ static void hid_irq_out(struct urb *urb)
 
 	clear_bit(HID_OUT_RUNNING, &usbhid->iofl);
 	spin_unlock_irqrestore(&usbhid->lock, flags);
+	usb_autopm_put_interface_async(usbhid->intf);
 	wake_up(&usbhid->wait);
 }
 
@@ -480,11 +480,13 @@ static void hid_ctrl(struct urb *urb)
 			wake_up(&usbhid->wait);
 		}
 		spin_unlock(&usbhid->lock);
+		usb_autopm_put_interface_async(usbhid->intf);
 		return;
 	}
 
 	clear_bit(HID_CTRL_RUNNING, &usbhid->iofl);
 	spin_unlock(&usbhid->lock);
+	usb_autopm_put_interface_async(usbhid->intf);
 	wake_up(&usbhid->wait);
 }
 
@@ -655,7 +657,7 @@ int usbhid_open(struct hid_device *hid)
 	mutex_lock(&hid_open_mut);
 	if (!hid->open++) {
 		res = usb_autopm_get_interface(usbhid->intf);
-		/* the device must be awake to reliable request remote wakeup */
+		/* the device must be awake to reliably request remote wakeup */
 		if (res < 0) {
 			hid->open--;
 			mutex_unlock(&hid_open_mut);
@@ -856,18 +858,6 @@ static void usbhid_restart_queues(struct usbhid_device *usbhid)
 	usbhid_restart_ctrl_queue(usbhid);
 }
 
-static void __usbhid_restart_queues(struct work_struct *work)
-{
-	struct usbhid_device *usbhid =
-		container_of(work, struct usbhid_device, restart_work);
-	int r;
-
-	r = usb_autopm_get_interface(usbhid->intf);
-	if (r < 0)
-		return;
-	usb_autopm_put_interface(usbhid->intf);
-}
-
 static void hid_free_buffers(struct usb_device *dev, struct hid_device *hid)
 {
 	struct usbhid_device *usbhid = hid->driver_data;
@@ -1204,7 +1194,6 @@ static int usbhid_probe(struct usb_interface *intf, const struct usb_device_id *
 
 	init_waitqueue_head(&usbhid->wait);
 	INIT_WORK(&usbhid->reset_work, hid_reset);
-	INIT_WORK(&usbhid->restart_work, __usbhid_restart_queues);
 	setup_timer(&usbhid->io_retry, hid_retry_timeout, (unsigned long) hid);
 	spin_lock_init(&usbhid->lock);
 
@@ -1239,7 +1228,6 @@ static void usbhid_disconnect(struct usb_interface *intf)
 static void hid_cancel_delayed_stuff(struct usbhid_device *usbhid)
 {
 	del_timer_sync(&usbhid->io_retry);
-	cancel_work_sync(&usbhid->restart_work);
 	cancel_work_sync(&usbhid->reset_work);
 }
 
@@ -1260,7 +1248,6 @@ static int hid_pre_reset(struct usb_interface *intf)
 	spin_lock_irq(&usbhid->lock);
 	set_bit(HID_RESET_PENDING, &usbhid->iofl);
 	spin_unlock_irq(&usbhid->lock);
-	cancel_work_sync(&usbhid->restart_work);
 	hid_cease_io(usbhid);
 
 	return 0;
@@ -1459,9 +1446,6 @@ static int __init hid_init(void)
 {
 	int retval = -ENOMEM;
 
-	resumption_waker = create_freezeable_workqueue("usbhid_resumer");
-	if (!resumption_waker)
-		goto no_queue;
 	retval = hid_register_driver(&hid_usb_driver);
 	if (retval)
 		goto hid_register_fail;
@@ -1479,8 +1463,6 @@ static int __init hid_init(void)
 usbhid_quirks_init_fail:
 	hid_unregister_driver(&hid_usb_driver);
 hid_register_fail:
-	destroy_workqueue(resumption_waker);
-no_queue:
 	return retval;
 }
 
@@ -1489,7 +1471,6 @@ static void __exit hid_exit(void)
 	usb_deregister(&hid_driver);
 	usbhid_quirks_exit();
 	hid_unregister_driver(&hid_usb_driver);
-	destroy_workqueue(resumption_waker);
 }
 
 module_init(hid_init);

drivers/hid/usbhid/usbhid.h

@@ -95,7 +95,6 @@ struct usbhid_device {
 	unsigned long stop_retry;                                       /* Time to give up, in jiffies */
 	unsigned int retry_delay;                                       /* Delay length in ms */
 	struct work_struct reset_work;                                  /* Task context for resets */
-	struct work_struct restart_work;				/* waking up for output to be done in a task */
 	wait_queue_head_t wait;						/* For sleeping */
 	int ledcount;							/* counting the number of active leds */
 };