1 files changed, 46 insertions, 72 deletions

diff --git a/drivers/usb/misc/appledisplay.c b/drivers/usb/misc/appledisplay.c
index ba6a5d6e618e..62b5a30edc42 100644
--- a/drivers/usb/misc/appledisplay.c
+++ b/drivers/usb/misc/appledisplay.c
@@ -1,23 +1,10 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  * Apple Cinema Display driver
  *
  * Copyright (C) 2006  Michael Hanselmann (linux-kernel@hansmi.ch)
  *
  * Thanks to Caskey L. Dickson for his work with acdctl.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
 
 #include <linux/kernel.h>
@@ -63,6 +50,8 @@ static const struct usb_device_id appledisplay_table[] = {
 	{ APPLEDISPLAY_DEVICE(0x9219) },
 	{ APPLEDISPLAY_DEVICE(0x921c) },
 	{ APPLEDISPLAY_DEVICE(0x921d) },
+	{ APPLEDISPLAY_DEVICE(0x9222) },
+	{ APPLEDISPLAY_DEVICE(0x9226) },
 	{ APPLEDISPLAY_DEVICE(0x9236) },
 
 	/* Terminating entry */
@@ -80,17 +69,15 @@ struct appledisplay {
 
 	struct delayed_work work;
 	int button_pressed;
-	spinlock_t lock;
+	struct mutex sysfslock;		/* concurrent read and write */
 };
 
 static atomic_t count_displays = ATOMIC_INIT(0);
-static struct workqueue_struct *wq;
 
 static void appledisplay_complete(struct urb *urb)
 {
 	struct appledisplay *pdata = urb->context;
 	struct device *dev = &pdata->udev->dev;
-	unsigned long flags;
 	int status = urb->status;
 	int retval;
 
@@ -102,6 +89,7 @@ static void appledisplay_complete(struct urb *urb)
 		dev_err(dev,
 			"OVERFLOW with data length %d, actual length is %d\n",
 			ACD_URB_BUFFER_LEN, pdata->urb->actual_length);
+		fallthrough;
 	case -ECONNRESET:
 	case -ENOENT:
 	case -ESHUTDOWN:
@@ -110,18 +98,21 @@ static void appledisplay_complete(struct urb *urb)
 			__func__, status);
 		return;
 	default:
-		dev_dbg(dev, "%s - nonzero urb status received: %d/n",
+		dev_dbg(dev, "%s - nonzero urb status received: %d\n",
 			__func__, status);
 		goto exit;
 	}
 
-	spin_lock_irqsave(&pdata->lock, flags);
-
 	switch(pdata->urbdata[1]) {
 	case ACD_BTN_BRIGHT_UP:
 	case ACD_BTN_BRIGHT_DOWN:
 		pdata->button_pressed = 1;
-		queue_delayed_work(wq, &pdata->work, 0);
+		/*
+		 * there is a window during which no device
+		 * is registered
+		 */
+		if (pdata->bd )
+			schedule_delayed_work(&pdata->work, 0);
 		break;
 	case ACD_BTN_NONE:
 	default:
@@ -129,8 +120,6 @@ static void appledisplay_complete(struct urb *urb)
 		break;
 	}
 
-	spin_unlock_irqrestore(&pdata->lock, flags);
-
 exit:
 	retval = usb_submit_urb(pdata->urb, GFP_ATOMIC);
 	if (retval) {
@@ -144,6 +133,7 @@ static int appledisplay_bl_update_status(struct backlight_device *bd)
 	struct appledisplay *pdata = bl_get_data(bd);
 	int retval;
 
+	mutex_lock(&pdata->sysfslock);
 	pdata->msgdata[0] = 0x10;
 	pdata->msgdata[1] = bd->props.brightness;
 
@@ -156,15 +146,20 @@ static int appledisplay_bl_update_status(struct backlight_device *bd)
 		0,
 		pdata->msgdata, 2,
 		ACD_USB_TIMEOUT);
+	mutex_unlock(&pdata->sysfslock);
 
-	return retval;
+	if (retval < 0)
+		return retval;
+	else
+		return 0;
 }
 
 static int appledisplay_bl_get_brightness(struct backlight_device *bd)
 {
 	struct appledisplay *pdata = bl_get_data(bd);
-	int retval;
+	int retval, brightness;
 
+	mutex_lock(&pdata->sysfslock);
 	retval = usb_control_msg(
 		pdata->udev,
 		usb_rcvctrlpipe(pdata->udev, 0),
@@ -174,11 +169,18 @@ static int appledisplay_bl_get_brightness(struct backlight_device *bd)
 		0,
 		pdata->msgdata, 2,
 		ACD_USB_TIMEOUT);
+	if (retval < 2) {
+		if (retval >= 0)
+			retval = -EMSGSIZE;
+	} else {
+		brightness = pdata->msgdata[1];
+	}
+	mutex_unlock(&pdata->sysfslock);
 
 	if (retval < 0)
 		return retval;
 	else
-		return pdata->msgdata[1];
+		return brightness;
 }
 
 static const struct backlight_ops appledisplay_bl_data = {
@@ -205,49 +207,40 @@ static int appledisplay_probe(struct usb_interface *iface,
 	const struct usb_device_id *id)
 {
 	struct backlight_properties props;
+	struct backlight_device *backlight;
 	struct appledisplay *pdata;
 	struct usb_device *udev = interface_to_usbdev(iface);
-	struct usb_host_interface *iface_desc;
 	struct usb_endpoint_descriptor *endpoint;
 	int int_in_endpointAddr = 0;
-	int i, retval = -ENOMEM, brightness;
+	int retval, brightness;
 	char bl_name[20];
 
 	/* set up the endpoint information */
 	/* use only the first interrupt-in endpoint */
-	iface_desc = iface->cur_altsetting;
-	for (i = 0; i < iface_desc->desc.bNumEndpoints; i++) {
-		endpoint = &iface_desc->endpoint[i].desc;
-		if (!int_in_endpointAddr && usb_endpoint_is_int_in(endpoint)) {
-			/* we found an interrupt in endpoint */
-			int_in_endpointAddr = endpoint->bEndpointAddress;
-			break;
-		}
-	}
-	if (!int_in_endpointAddr) {
+	retval = usb_find_int_in_endpoint(iface->cur_altsetting, &endpoint);
+	if (retval) {
 		dev_err(&iface->dev, "Could not find int-in endpoint\n");
-		return -EIO;
+		return retval;
 	}
 
+	int_in_endpointAddr = endpoint->bEndpointAddress;
+
 	/* allocate memory for our device state and initialize it */
 	pdata = kzalloc(sizeof(struct appledisplay), GFP_KERNEL);
 	if (!pdata) {
 		retval = -ENOMEM;
-		dev_err(&iface->dev, "Out of memory\n");
 		goto error;
 	}
 
 	pdata->udev = udev;
 
-	spin_lock_init(&pdata->lock);
 	INIT_DELAYED_WORK(&pdata->work, appledisplay_work);
+	mutex_init(&pdata->sysfslock);
 
 	/* Allocate buffer for control messages */
 	pdata->msgdata = kmalloc(ACD_MSG_BUFFER_LEN, GFP_KERNEL);
 	if (!pdata->msgdata) {
 		retval = -ENOMEM;
-		dev_err(&iface->dev,
-			"Allocating buffer for control messages failed\n");
 		goto error;
 	}
 
@@ -255,7 +248,6 @@ static int appledisplay_probe(struct usb_interface *iface,
 	pdata->urb = usb_alloc_urb(0, GFP_KERNEL);
 	if (!pdata->urb) {
 		retval = -ENOMEM;
-		dev_err(&iface->dev, "Allocating URB failed\n");
 		goto error;
 	}
 
@@ -273,6 +265,7 @@ static int appledisplay_probe(struct usb_interface *iface,
 		usb_rcvintpipe(udev, int_in_endpointAddr),
 		pdata->urbdata, ACD_URB_BUFFER_LEN, appledisplay_complete,
 		pdata, 1);
+	pdata->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
 	if (usb_submit_urb(pdata->urb, GFP_KERNEL)) {
 		retval = -EIO;
 		dev_err(&iface->dev, "Submitting URB failed\n");
@@ -285,13 +278,14 @@ static int appledisplay_probe(struct usb_interface *iface,
 	memset(&props, 0, sizeof(struct backlight_properties));
 	props.type = BACKLIGHT_RAW;
 	props.max_brightness = 0xff;
-	pdata->bd = backlight_device_register(bl_name, NULL, pdata,
+	backlight = backlight_device_register(bl_name, NULL, pdata,
 					      &appledisplay_bl_data, &props);
-	if (IS_ERR(pdata->bd)) {
+	if (IS_ERR(backlight)) {
 		dev_err(&iface->dev, "Backlight registration failed\n");
-		retval = PTR_ERR(pdata->bd);
+		retval = PTR_ERR(backlight);
 		goto error;
 	}
+	pdata->bd = backlight;
 
 	/* Try to get brightness */
 	brightness = appledisplay_bl_get_brightness(pdata->bd);
@@ -317,12 +311,12 @@ error:
 	if (pdata) {
 		if (pdata->urb) {
 			usb_kill_urb(pdata->urb);
-			if (pdata->urbdata)
-				usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
+			cancel_delayed_work_sync(&pdata->work);
+			usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
 					pdata->urbdata, pdata->urb->transfer_dma);
 			usb_free_urb(pdata->urb);
 		}
-		if (pdata->bd && !IS_ERR(pdata->bd))
+		if (!IS_ERR(pdata->bd))
 			backlight_device_unregister(pdata->bd);
 		kfree(pdata->msgdata);
 	}
@@ -337,7 +331,7 @@ static void appledisplay_disconnect(struct usb_interface *iface)
 
 	if (pdata) {
 		usb_kill_urb(pdata->urb);
-		cancel_delayed_work(&pdata->work);
+		cancel_delayed_work_sync(&pdata->work);
 		backlight_device_unregister(pdata->bd);
 		usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN,
 			pdata->urbdata, pdata->urb->transfer_dma);
@@ -355,28 +349,8 @@ static struct usb_driver appledisplay_driver = {
 	.disconnect	= appledisplay_disconnect,
 	.id_table	= appledisplay_table,
 };
-
-static int __init appledisplay_init(void)
-{
-	wq = create_singlethread_workqueue("appledisplay");
-	if (!wq) {
-		printk(KERN_ERR "appledisplay: Could not create work queue\n");
-		return -ENOMEM;
-	}
-
-	return usb_register(&appledisplay_driver);
-}
-
-static void __exit appledisplay_exit(void)
-{
-	flush_workqueue(wq);
-	destroy_workqueue(wq);
-	usb_deregister(&appledisplay_driver);
-}
+module_usb_driver(appledisplay_driver);
 
 MODULE_AUTHOR("Michael Hanselmann");
 MODULE_DESCRIPTION("Apple Cinema Display driver");
 MODULE_LICENSE("GPL");
-
-module_init(appledisplay_init);
-module_exit(appledisplay_exit);