1 files changed, 139 insertions, 47 deletions

diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index c6f6560d436..a051a7a2b1b 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -13,6 +13,7 @@
  */
 #include <linux/kernel.h>
 #include <linux/errno.h>
+#include <linux/ioctl.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -32,8 +33,6 @@
 #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 |
@@ -41,20 +40,6 @@ 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! */
-	},
 	{ }
 };
 
@@ -72,6 +57,7 @@ MODULE_DEVICE_TABLE (usb, wdm_ids);
 #define WDM_RESPONDING		7
 #define WDM_SUSPENDING		8
 #define WDM_RESETTING		9
+#define WDM_OVERFLOW		10
 
 #define WDM_MAX			16
 
@@ -115,6 +101,7 @@ struct wdm_device {
 	struct work_struct	rxwork;
 	int			werr;
 	int			rerr;
+	int                     resp_count;
 
 	struct list_head	device_list;
 	int			(*manage_power)(struct usb_interface *, int);
@@ -125,12 +112,14 @@ static struct usb_driver wdm_driver;
 /* return intfdata if we own the interface, else look up intf in the list */
 static struct wdm_device *wdm_find_device(struct usb_interface *intf)
 {
-	struct wdm_device *desc = NULL;
+	struct wdm_device *desc;
 
 	spin_lock(&wdm_device_list_lock);
 	list_for_each_entry(desc, &wdm_device_list, device_list)
 		if (desc->intf == intf)
-			break;
+			goto found;
+	desc = NULL;
+found:
 	spin_unlock(&wdm_device_list_lock);
 
 	return desc;
@@ -138,12 +127,14 @@ static struct wdm_device *wdm_find_device(struct usb_interface *intf)
 
 static struct wdm_device *wdm_find_device_by_minor(int minor)
 {
-	struct wdm_device *desc = NULL;
+	struct wdm_device *desc;
 
 	spin_lock(&wdm_device_list_lock);
 	list_for_each_entry(desc, &wdm_device_list, device_list)
 		if (desc->intf->minor == minor)
-			break;
+			goto found;
+	desc = NULL;
+found:
 	spin_unlock(&wdm_device_list_lock);
 
 	return desc;
@@ -157,8 +148,9 @@ static void wdm_out_callback(struct urb *urb)
 	spin_lock(&desc->iuspin);
 	desc->werr = urb->status;
 	spin_unlock(&desc->iuspin);
-	clear_bit(WDM_IN_USE, &desc->flags);
 	kfree(desc->outbuf);
+	desc->outbuf = NULL;
+	clear_bit(WDM_IN_USE, &desc->flags);
 	wake_up(&desc->wait);
 }
 
@@ -166,6 +158,7 @@ static void wdm_in_callback(struct urb *urb)
 {
 	struct wdm_device *desc = urb->context;
 	int status = urb->status;
+	int length = urb->actual_length;
 
 	spin_lock(&desc->iuspin);
 	clear_bit(WDM_RESPONDING, &desc->flags);
@@ -196,9 +189,17 @@ static void wdm_in_callback(struct urb *urb)
 	}
 
 	desc->rerr = status;
-	desc->reslength = urb->actual_length;
-	memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
-	desc->length += desc->reslength;
+	if (length + desc->length > desc->wMaxCommand) {
+		/* The buffer would overflow */
+		set_bit(WDM_OVERFLOW, &desc->flags);
+	} else {
+		/* we may already be in overflow */
+		if (!test_bit(WDM_OVERFLOW, &desc->flags)) {
+			memmove(desc->ubuf + desc->length, desc->inbuf, length);
+			desc->length += length;
+			desc->reslength = length;
+		}
+	}
 skip_error:
 	wake_up(&desc->wait);
 
@@ -209,6 +210,7 @@ skip_error:
 static void wdm_int_callback(struct urb *urb)
 {
 	int rv = 0;
+	int responding;
 	int status = urb->status;
 	struct wdm_device *desc;
 	struct usb_cdc_notification *dr;
@@ -252,6 +254,10 @@ static void wdm_int_callback(struct urb *urb)
 			"NOTIFY_NETWORK_CONNECTION %s network",
 			dr->wValue ? "connected to" : "disconnected from");
 		goto exit;
+	case USB_CDC_NOTIFY_SPEED_CHANGE:
+		dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)",
+			urb->actual_length);
+		goto exit;
 	default:
 		clear_bit(WDM_POLL_RUNNING, &desc->flags);
 		dev_err(&desc->intf->dev,
@@ -261,9 +267,9 @@ static void wdm_int_callback(struct urb *urb)
 	}
 
 	spin_lock(&desc->iuspin);
-	clear_bit(WDM_READ, &desc->flags);
-	set_bit(WDM_RESPONDING, &desc->flags);
-	if (!test_bit(WDM_DISCONNECTING, &desc->flags)
+	responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
+	if (!desc->resp_count++ && !responding
+		&& !test_bit(WDM_DISCONNECTING, &desc->flags)
 		&& !test_bit(WDM_SUSPENDING, &desc->flags)) {
 		rv = usb_submit_urb(desc->response, GFP_ATOMIC);
 		dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
@@ -308,9 +314,6 @@ static void free_urbs(struct wdm_device *desc)
 
 static void cleanup(struct wdm_device *desc)
 {
-	spin_lock(&wdm_device_list_lock);
-	list_del(&desc->device_list);
-	spin_unlock(&wdm_device_list_lock);
 	kfree(desc->sbuf);
 	kfree(desc->inbuf);
 	kfree(desc->orq);
@@ -338,7 +341,7 @@ static ssize_t wdm_write
 	if (we < 0)
 		return -EIO;
 
-	desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
+	buf = kmalloc(count, GFP_KERNEL);
 	if (!buf) {
 		rv = -ENOMEM;
 		goto outnl;
@@ -368,6 +371,7 @@ static ssize_t wdm_write
 	r = usb_autopm_get_interface(desc->intf);
 	if (r < 0) {
 		kfree(buf);
+		rv = usb_translate_errors(r);
 		goto outnp;
 	}
 
@@ -383,6 +387,7 @@ static ssize_t wdm_write
 
 	if (r < 0) {
 		kfree(buf);
+		rv = r;
 		goto out;
 	}
 
@@ -406,12 +411,15 @@ static ssize_t wdm_write
 	req->wIndex = desc->inum;
 	req->wLength = cpu_to_le16(count);
 	set_bit(WDM_IN_USE, &desc->flags);
+	desc->outbuf = buf;
 
 	rv = usb_submit_urb(desc->command, GFP_KERNEL);
 	if (rv < 0) {
 		kfree(buf);
+		desc->outbuf = NULL;
 		clear_bit(WDM_IN_USE, &desc->flags);
 		dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
+		rv = usb_translate_errors(rv);
 	} else {
 		dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
 			req->wIndex);
@@ -424,6 +432,38 @@ outnl:
 	return rv < 0 ? rv : count;
 }
 
+/*
+ * clear WDM_READ flag and possibly submit the read urb if resp_count
+ * is non-zero.
+ *
+ * Called with desc->iuspin locked
+ */
+static int clear_wdm_read_flag(struct wdm_device *desc)
+{
+	int rv = 0;
+
+	clear_bit(WDM_READ, &desc->flags);
+
+	/* submit read urb only if the device is waiting for it */
+	if (!desc->resp_count || !--desc->resp_count)
+		goto out;
+
+	set_bit(WDM_RESPONDING, &desc->flags);
+	spin_unlock_irq(&desc->iuspin);
+	rv = usb_submit_urb(desc->response, GFP_KERNEL);
+	spin_lock_irq(&desc->iuspin);
+	if (rv) {
+		dev_err(&desc->intf->dev,
+			"usb_submit_urb failed with result %d\n", rv);
+
+		/* make sure the next notification trigger a submit */
+		clear_bit(WDM_RESPONDING, &desc->flags);
+		desc->resp_count = 0;
+	}
+out:
+	return rv;
+}
+
 static ssize_t wdm_read
 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 {
@@ -444,6 +484,11 @@ retry:
 			rv = -ENODEV;
 			goto err;
 		}
+		if (test_bit(WDM_OVERFLOW, &desc->flags)) {
+			clear_bit(WDM_OVERFLOW, &desc->flags);
+			rv = -ENOBUFS;
+			goto err;
+		}
 		i++;
 		if (file->f_flags & O_NONBLOCK) {
 			if (!test_bit(WDM_READ, &desc->flags)) {
@@ -487,8 +532,13 @@ retry:
 			spin_unlock_irq(&desc->iuspin);
 			goto retry;
 		}
+
 		if (!desc->reslength) { /* zero length read */
+			dev_dbg(&desc->intf->dev, "%s: zero length - clearing WDM_READ\n", __func__);
+			rv = clear_wdm_read_flag(desc);
 			spin_unlock_irq(&desc->iuspin);
+			if (rv < 0)
+				goto err;
 			goto retry;
 		}
 		cntr = desc->length;
@@ -511,10 +561,8 @@ retry:
 	desc->length -= cntr;
 	/* in case we had outstanding data */
 	if (!desc->length)
-		clear_bit(WDM_READ, &desc->flags);
-
+		clear_wdm_read_flag(desc);
 	spin_unlock_irq(&desc->iuspin);
-
 	rv = cntr;
 
 err:
@@ -527,11 +575,13 @@ static int wdm_flush(struct file *file, fl_owner_t id)
 	struct wdm_device *desc = file->private_data;
 
 	wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
-	if (desc->werr < 0)
+
+	/* cannot dereference desc->intf if WDM_DISCONNECTING */
+	if (desc->werr < 0 && !test_bit(WDM_DISCONNECTING, &desc->flags))
 		dev_err(&desc->intf->dev, "Error in flush path: %d\n",
 			desc->werr);
 
-	return desc->werr;
+	return usb_translate_errors(desc->werr);
 }
 
 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
@@ -542,7 +592,7 @@ static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
 
 	spin_lock_irqsave(&desc->iuspin, flags);
 	if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
-		mask = POLLERR;
+		mask = POLLHUP | POLLERR;
 		spin_unlock_irqrestore(&desc->iuspin, flags);
 		goto desc_out;
 	}
@@ -593,6 +643,7 @@ static int wdm_open(struct inode *inode, struct file *file)
 			desc->count--;
 			dev_err(&desc->intf->dev,
 				"Error submitting int urb - %d\n", rv);
+			rv = usb_translate_errors(rv);
 		}
 	} else {
 		rv = 0;
@@ -618,15 +669,39 @@ static int wdm_release(struct inode *inode, struct file *file)
 	mutex_unlock(&desc->wlock);
 
 	if (!desc->count) {
-		dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
-		kill_urbs(desc);
-		if (!test_bit(WDM_DISCONNECTING, &desc->flags))
+		if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
+			dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
+			kill_urbs(desc);
+			spin_lock_irq(&desc->iuspin);
+			desc->resp_count = 0;
+			spin_unlock_irq(&desc->iuspin);
 			desc->manage_power(desc->intf, 0);
+		} else {
+			/* must avoid dev_printk here as desc->intf is invalid */
+			pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
+			cleanup(desc);
+		}
 	}
 	mutex_unlock(&wdm_mutex);
 	return 0;
 }
 
+static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct wdm_device *desc = file->private_data;
+	int rv = 0;
+
+	switch (cmd) {
+	case IOCTL_WDM_MAX_COMMAND:
+		if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand)))
+			rv = -EFAULT;
+		break;
+	default:
+		rv = -ENOTTY;
+	}
+	return rv;
+}
+
 static const struct file_operations wdm_fops = {
 	.owner =	THIS_MODULE,
 	.read =		wdm_read,
@@ -635,6 +710,8 @@ static const struct file_operations wdm_fops = {
 	.flush =	wdm_flush,
 	.release =	wdm_release,
 	.poll =		wdm_poll,
+	.unlocked_ioctl = wdm_ioctl,
+	.compat_ioctl = wdm_ioctl,
 	.llseek =	noop_llseek,
 };
 
@@ -649,16 +726,20 @@ static void wdm_rxwork(struct work_struct *work)
 {
 	struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
 	unsigned long flags;
-	int rv;
+	int rv = 0;
+	int responding;
 
 	spin_lock_irqsave(&desc->iuspin, flags);
 	if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 		spin_unlock_irqrestore(&desc->iuspin, flags);
 	} else {
+		responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
 		spin_unlock_irqrestore(&desc->iuspin, flags);
-		rv = usb_submit_urb(desc->response, GFP_KERNEL);
+		if (!responding)
+			rv = usb_submit_urb(desc->response, GFP_KERNEL);
 		if (rv < 0 && rv != -EPERM) {
 			spin_lock_irqsave(&desc->iuspin, flags);
+			clear_bit(WDM_RESPONDING, &desc->flags);
 			if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 				schedule_work(&desc->rxwork);
 			spin_unlock_irqrestore(&desc->iuspin, flags);
@@ -768,6 +849,9 @@ static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor
 out:
 	return rv;
 err:
+	spin_lock(&wdm_device_list_lock);
+	list_del(&desc->device_list);
+	spin_unlock(&wdm_device_list_lock);
 	cleanup(desc);
 	return rv;
 }
@@ -776,13 +860,11 @@ static int wdm_manage_power(struct usb_interface *intf, int on)
 {
 	/* need autopm_get/put here to ensure the usbcore sees the new value */
 	int rv = usb_autopm_get_interface(intf);
-	if (rv < 0)
-		goto err;
 
 	intf->needs_remote_wakeup = on;
-	usb_autopm_put_interface(intf);
-err:
-	return rv;
+	if (!rv)
+		usb_autopm_put_interface(intf);
+	return 0;
 }
 
 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
@@ -893,8 +975,16 @@ static void wdm_disconnect(struct usb_interface *intf)
 	cancel_work_sync(&desc->rxwork);
 	mutex_unlock(&desc->wlock);
 	mutex_unlock(&desc->rlock);
+
+	/* the desc->intf pointer used as list key is now invalid */
+	spin_lock(&wdm_device_list_lock);
+	list_del(&desc->device_list);
+	spin_unlock(&wdm_device_list_lock);
+
 	if (!desc->count)
 		cleanup(desc);
+	else
+		dev_dbg(&intf->dev, "%s: %d open files - postponing cleanup\n", __func__, desc->count);
 	mutex_unlock(&wdm_mutex);
 }
 
@@ -992,6 +1082,7 @@ static int wdm_post_reset(struct usb_interface *intf)
 	struct wdm_device *desc = wdm_find_device(intf);
 	int rv;
 
+	clear_bit(WDM_OVERFLOW, &desc->flags);
 	clear_bit(WDM_RESETTING, &desc->flags);
 	rv = recover_from_urb_loss(desc);
 	mutex_unlock(&desc->wlock);
@@ -1012,6 +1103,7 @@ static struct usb_driver wdm_driver = {
 	.post_reset =	wdm_post_reset,
 	.id_table =	wdm_ids,
 	.supports_autosuspend = 1,
+	.disable_hub_initiated_lpm = 1,
 };
 
 module_usb_driver(wdm_driver);