1 files changed, 105 insertions, 80 deletions

diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 1c50baff7725..6037b503153f 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -31,6 +31,8 @@
 #define DRIVER_AUTHOR "Oliver Neukum"
 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
 
+#define HUAWEI_VENDOR_ID	0x12D1
+
 static const struct usb_device_id wdm_ids[] = {
 	{
 		.match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
@@ -38,6 +40,20 @@ static const struct usb_device_id wdm_ids[] = {
 		.bInterfaceClass = USB_CLASS_COMM,
 		.bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
 	},
+	{
+		/* 
+		 * Huawei E392, E398 and possibly other Qualcomm based modems
+		 * embed the Qualcomm QMI protocol inside CDC on CDC ECM like
+		 * control interfaces.  Userspace access to this is required
+		 * to configure the accompanying data interface
+		 */
+		.match_flags        = USB_DEVICE_ID_MATCH_VENDOR |
+					USB_DEVICE_ID_MATCH_INT_INFO,
+		.idVendor           = HUAWEI_VENDOR_ID,
+		.bInterfaceClass    = USB_CLASS_VENDOR_SPEC,
+		.bInterfaceSubClass = 1,
+		.bInterfaceProtocol = 9, /* NOTE: CDC ECM control interface! */
+	},
 	{ }
 };
 
@@ -54,9 +70,12 @@ MODULE_DEVICE_TABLE (usb, wdm_ids);
 #define WDM_POLL_RUNNING	6
 #define WDM_RESPONDING		7
 #define WDM_SUSPENDING		8
+#define WDM_RESETTING		9
 
 #define WDM_MAX			16
 
+/* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
+#define WDM_DEFAULT_BUFSIZE	256
 
 static DEFINE_MUTEX(wdm_mutex);
 
@@ -80,7 +99,6 @@ struct wdm_device {
 	u16			bufsize;
 	u16			wMaxCommand;
 	u16			wMaxPacketSize;
-	u16			bMaxPacketSize0;
 	__le16			inum;
 	int			reslength;
 	int			length;
@@ -88,7 +106,8 @@ struct wdm_device {
 	int			count;
 	dma_addr_t		shandle;
 	dma_addr_t		ihandle;
-	struct mutex		lock;
+	struct mutex		wlock;
+	struct mutex		rlock;
 	wait_queue_head_t	wait;
 	struct work_struct	rxwork;
 	int			werr;
@@ -159,11 +178,9 @@ static void wdm_int_callback(struct urb *urb)
 	int rv = 0;
 	int status = urb->status;
 	struct wdm_device *desc;
-	struct usb_ctrlrequest *req;
 	struct usb_cdc_notification *dr;
 
 	desc = urb->context;
-	req = desc->irq;
 	dr = (struct usb_cdc_notification *)desc->sbuf;
 
 	if (status) {
@@ -210,24 +227,6 @@ static void wdm_int_callback(struct urb *urb)
 		goto exit;
 	}
 
-	req->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
-	req->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
-	req->wValue = 0;
-	req->wIndex = desc->inum;
-	req->wLength = cpu_to_le16(desc->wMaxCommand);
-
-	usb_fill_control_urb(
-		desc->response,
-		interface_to_usbdev(desc->intf),
-		/* using common endpoint 0 */
-		usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
-		(unsigned char *)req,
-		desc->inbuf,
-		desc->wMaxCommand,
-		wdm_in_callback,
-		desc
-	);
-	desc->response->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 	spin_lock(&desc->iuspin);
 	clear_bit(WDM_READ, &desc->flags);
 	set_bit(WDM_RESPONDING, &desc->flags);
@@ -276,14 +275,8 @@ static void free_urbs(struct wdm_device *desc)
 
 static void cleanup(struct wdm_device *desc)
 {
-	usb_free_coherent(interface_to_usbdev(desc->intf),
-			  desc->wMaxPacketSize,
-			  desc->sbuf,
-			  desc->validity->transfer_dma);
-	usb_free_coherent(interface_to_usbdev(desc->intf),
-			  desc->bMaxPacketSize0,
-			  desc->inbuf,
-			  desc->response->transfer_dma);
+	kfree(desc->sbuf);
+	kfree(desc->inbuf);
 	kfree(desc->orq);
 	kfree(desc->irq);
 	kfree(desc->ubuf);
@@ -323,7 +316,7 @@ static ssize_t wdm_write
 	}
 
 	/* concurrent writes and disconnect */
-	r = mutex_lock_interruptible(&desc->lock);
+	r = mutex_lock_interruptible(&desc->wlock);
 	rv = -ERESTARTSYS;
 	if (r) {
 		kfree(buf);
@@ -348,6 +341,10 @@ static ssize_t wdm_write
 	else
 		if (test_bit(WDM_IN_USE, &desc->flags))
 			r = -EAGAIN;
+
+	if (test_bit(WDM_RESETTING, &desc->flags))
+		r = -EIO;
+
 	if (r < 0) {
 		kfree(buf);
 		goto out;
@@ -386,7 +383,7 @@ static ssize_t wdm_write
 out:
 	usb_autopm_put_interface(desc->intf);
 outnp:
-	mutex_unlock(&desc->lock);
+	mutex_unlock(&desc->wlock);
 outnl:
 	return rv < 0 ? rv : count;
 }
@@ -394,16 +391,17 @@ outnl:
 static ssize_t wdm_read
 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 {
-	int rv, cntr = 0;
+	int rv, cntr;
 	int i = 0;
 	struct wdm_device *desc = file->private_data;
 
 
-	rv = mutex_lock_interruptible(&desc->lock); /*concurrent reads */
+	rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
 	if (rv < 0)
 		return -ERESTARTSYS;
 
-	if (desc->length == 0) {
+	cntr = ACCESS_ONCE(desc->length);
+	if (cntr == 0) {
 		desc->read = 0;
 retry:
 		if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
@@ -427,6 +425,10 @@ retry:
 			rv = -ENODEV;
 			goto err;
 		}
+		if (test_bit(WDM_RESETTING, &desc->flags)) {
+			rv = -EIO;
+			goto err;
+		}
 		usb_mark_last_busy(interface_to_usbdev(desc->intf));
 		if (rv < 0) {
 			rv = -ERESTARTSYS;
@@ -453,17 +455,20 @@ retry:
 			spin_unlock_irq(&desc->iuspin);
 			goto retry;
 		}
-		clear_bit(WDM_READ, &desc->flags);
+		cntr = desc->length;
 		spin_unlock_irq(&desc->iuspin);
 	}
 
-	cntr = count > desc->length ? desc->length : count;
+	if (cntr > count)
+		cntr = count;
 	rv = copy_to_user(buffer, desc->ubuf, cntr);
 	if (rv > 0) {
 		rv = -EFAULT;
 		goto err;
 	}
 
+	spin_lock_irq(&desc->iuspin);
+
 	for (i = 0; i < desc->length - cntr; i++)
 		desc->ubuf[i] = desc->ubuf[i + cntr];
 
@@ -471,10 +476,13 @@ retry:
 	/* in case we had outstanding data */
 	if (!desc->length)
 		clear_bit(WDM_READ, &desc->flags);
+
+	spin_unlock_irq(&desc->iuspin);
+
 	rv = cntr;
 
 err:
-	mutex_unlock(&desc->lock);
+	mutex_unlock(&desc->rlock);
 	return rv;
 }
 
@@ -540,7 +548,8 @@ static int wdm_open(struct inode *inode, struct file *file)
 	}
 	intf->needs_remote_wakeup = 1;
 
-	mutex_lock(&desc->lock);
+	/* using write lock to protect desc->count */
+	mutex_lock(&desc->wlock);
 	if (!desc->count++) {
 		desc->werr = 0;
 		desc->rerr = 0;
@@ -553,7 +562,7 @@ static int wdm_open(struct inode *inode, struct file *file)
 	} else {
 		rv = 0;
 	}
-	mutex_unlock(&desc->lock);
+	mutex_unlock(&desc->wlock);
 	usb_autopm_put_interface(desc->intf);
 out:
 	mutex_unlock(&wdm_mutex);
@@ -565,9 +574,11 @@ static int wdm_release(struct inode *inode, struct file *file)
 	struct wdm_device *desc = file->private_data;
 
 	mutex_lock(&wdm_mutex);
-	mutex_lock(&desc->lock);
+
+	/* using write lock to protect desc->count */
+	mutex_lock(&desc->wlock);
 	desc->count--;
-	mutex_unlock(&desc->lock);
+	mutex_unlock(&desc->wlock);
 
 	if (!desc->count) {
 		dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
@@ -623,14 +634,13 @@ static void wdm_rxwork(struct work_struct *work)
 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
 {
 	int rv = -EINVAL;
-	struct usb_device *udev = interface_to_usbdev(intf);
 	struct wdm_device *desc;
 	struct usb_host_interface *iface;
 	struct usb_endpoint_descriptor *ep;
 	struct usb_cdc_dmm_desc *dmhd;
 	u8 *buffer = intf->altsetting->extra;
 	int buflen = intf->altsetting->extralen;
-	u16 maxcom = 0;
+	u16 maxcom = WDM_DEFAULT_BUFSIZE;
 
 	if (!buffer)
 		goto out;
@@ -665,7 +675,8 @@ next_desc:
 	desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
 	if (!desc)
 		goto out;
-	mutex_init(&desc->lock);
+	mutex_init(&desc->rlock);
+	mutex_init(&desc->wlock);
 	spin_lock_init(&desc->iuspin);
 	init_waitqueue_head(&desc->wait);
 	desc->wMaxCommand = maxcom;
@@ -683,7 +694,6 @@ next_desc:
 		goto err;
 
 	desc->wMaxPacketSize = usb_endpoint_maxp(ep);
-	desc->bMaxPacketSize0 = udev->descriptor.bMaxPacketSize0;
 
 	desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
 	if (!desc->orq)
@@ -708,19 +718,13 @@ next_desc:
 	if (!desc->ubuf)
 		goto err;
 
-	desc->sbuf = usb_alloc_coherent(interface_to_usbdev(intf),
-					desc->wMaxPacketSize,
-					GFP_KERNEL,
-					&desc->validity->transfer_dma);
+	desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
 	if (!desc->sbuf)
 		goto err;
 
-	desc->inbuf = usb_alloc_coherent(interface_to_usbdev(intf),
-					 desc->bMaxPacketSize0,
-					 GFP_KERNEL,
-					 &desc->response->transfer_dma);
+	desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
 	if (!desc->inbuf)
-		goto err2;
+		goto err;
 
 	usb_fill_int_urb(
 		desc->validity,
@@ -732,30 +736,39 @@ next_desc:
 		desc,
 		ep->bInterval
 	);
-	desc->validity->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+
+	desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
+	desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
+	desc->irq->wValue = 0;
+	desc->irq->wIndex = desc->inum;
+	desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
+
+	usb_fill_control_urb(
+		desc->response,
+		interface_to_usbdev(intf),
+		/* using common endpoint 0 */
+		usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
+		(unsigned char *)desc->irq,
+		desc->inbuf,
+		desc->wMaxCommand,
+		wdm_in_callback,
+		desc
+	);
 
 	usb_set_intfdata(intf, desc);
 	rv = usb_register_dev(intf, &wdm_class);
 	if (rv < 0)
-		goto err3;
+		goto err2;
 	else
-		dev_info(&intf->dev, "cdc-wdm%d: USB WDM device\n",
-			intf->minor - WDM_MINOR_BASE);
+		dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
 out:
 	return rv;
-err3:
-	usb_set_intfdata(intf, NULL);
-	usb_free_coherent(interface_to_usbdev(desc->intf),
-			  desc->bMaxPacketSize0,
-			desc->inbuf,
-			desc->response->transfer_dma);
 err2:
-	usb_free_coherent(interface_to_usbdev(desc->intf),
-			  desc->wMaxPacketSize,
-			  desc->sbuf,
-			  desc->validity->transfer_dma);
+	usb_set_intfdata(intf, NULL);
 err:
 	free_urbs(desc);
+	kfree(desc->inbuf);
+	kfree(desc->sbuf);
 	kfree(desc->ubuf);
 	kfree(desc->orq);
 	kfree(desc->irq);
@@ -779,11 +792,13 @@ static void wdm_disconnect(struct usb_interface *intf)
 	/* to terminate pending flushes */
 	clear_bit(WDM_IN_USE, &desc->flags);
 	spin_unlock_irqrestore(&desc->iuspin, flags);
-	mutex_lock(&desc->lock);
+	wake_up_all(&desc->wait);
+	mutex_lock(&desc->rlock);
+	mutex_lock(&desc->wlock);
 	kill_urbs(desc);
 	cancel_work_sync(&desc->rxwork);
-	mutex_unlock(&desc->lock);
-	wake_up_all(&desc->wait);
+	mutex_unlock(&desc->wlock);
+	mutex_unlock(&desc->rlock);
 	if (!desc->count)
 		cleanup(desc);
 	mutex_unlock(&wdm_mutex);
@@ -798,8 +813,10 @@ static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 	dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
 
 	/* if this is an autosuspend the caller does the locking */
-	if (!PMSG_IS_AUTO(message))
-		mutex_lock(&desc->lock);
+	if (!PMSG_IS_AUTO(message)) {
+		mutex_lock(&desc->rlock);
+		mutex_lock(&desc->wlock);
+	}
 	spin_lock_irq(&desc->iuspin);
 
 	if (PMSG_IS_AUTO(message) &&
@@ -815,8 +832,10 @@ static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
 		kill_urbs(desc);
 		cancel_work_sync(&desc->rxwork);
 	}
-	if (!PMSG_IS_AUTO(message))
-		mutex_unlock(&desc->lock);
+	if (!PMSG_IS_AUTO(message)) {
+		mutex_unlock(&desc->wlock);
+		mutex_unlock(&desc->rlock);
+	}
 
 	return rv;
 }
@@ -854,9 +873,6 @@ static int wdm_pre_reset(struct usb_interface *intf)
 {
 	struct wdm_device *desc = usb_get_intfdata(intf);
 
-	mutex_lock(&desc->lock);
-	kill_urbs(desc);
-
 	/*
 	 * we notify everybody using poll of
 	 * an exceptional situation
@@ -864,9 +880,16 @@ static int wdm_pre_reset(struct usb_interface *intf)
 	 * message from the device is lost
 	 */
 	spin_lock_irq(&desc->iuspin);
+	set_bit(WDM_RESETTING, &desc->flags);	/* inform read/write */
+	set_bit(WDM_READ, &desc->flags);	/* unblock read */
+	clear_bit(WDM_IN_USE, &desc->flags);	/* unblock write */
 	desc->rerr = -EINTR;
 	spin_unlock_irq(&desc->iuspin);
 	wake_up_all(&desc->wait);
+	mutex_lock(&desc->rlock);
+	mutex_lock(&desc->wlock);
+	kill_urbs(desc);
+	cancel_work_sync(&desc->rxwork);
 	return 0;
 }
 
@@ -875,8 +898,10 @@ static int wdm_post_reset(struct usb_interface *intf)
 	struct wdm_device *desc = usb_get_intfdata(intf);
 	int rv;
 
+	clear_bit(WDM_RESETTING, &desc->flags);
 	rv = recover_from_urb_loss(desc);
-	mutex_unlock(&desc->lock);
+	mutex_unlock(&desc->wlock);
+	mutex_unlock(&desc->rlock);
 	return 0;
 }