Update Linux to v5.4.148

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz

Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 62f4fb9..c0604c6 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -147,17 +147,29 @@
 #define acm_send_break(acm, ms) \
 	acm_ctrl_msg(acm, USB_CDC_REQ_SEND_BREAK, ms, NULL, 0)
 
-static void acm_kill_urbs(struct acm *acm)
+static void acm_poison_urbs(struct acm *acm)
 {
 	int i;
 
-	usb_kill_urb(acm->ctrlurb);
+	usb_poison_urb(acm->ctrlurb);
 	for (i = 0; i < ACM_NW; i++)
-		usb_kill_urb(acm->wb[i].urb);
+		usb_poison_urb(acm->wb[i].urb);
 	for (i = 0; i < acm->rx_buflimit; i++)
-		usb_kill_urb(acm->read_urbs[i]);
+		usb_poison_urb(acm->read_urbs[i]);
 }
 
+static void acm_unpoison_urbs(struct acm *acm)
+{
+	int i;
+
+	for (i = 0; i < acm->rx_buflimit; i++)
+		usb_unpoison_urb(acm->read_urbs[i]);
+	for (i = 0; i < ACM_NW; i++)
+		usb_unpoison_urb(acm->wb[i].urb);
+	usb_unpoison_urb(acm->ctrlurb);
+}
+
+
 /*
  * Write buffer management.
  * All of these assume proper locks taken by the caller.
@@ -225,9 +237,10 @@
 
 	rc = usb_submit_urb(wb->urb, GFP_ATOMIC);
 	if (rc < 0) {
-		dev_err(&acm->data->dev,
-			"%s - usb_submit_urb(write bulk) failed: %d\n",
-			__func__, rc);
+		if (rc != -EPERM)
+			dev_err(&acm->data->dev,
+				"%s - usb_submit_urb(write bulk) failed: %d\n",
+				__func__, rc);
 		acm_write_done(acm, wb);
 	}
 	return rc;
@@ -312,8 +325,10 @@
 			acm->iocount.dsr++;
 		if (difference & ACM_CTRL_DCD)
 			acm->iocount.dcd++;
-		if (newctrl & ACM_CTRL_BRK)
+		if (newctrl & ACM_CTRL_BRK) {
 			acm->iocount.brk++;
+			tty_insert_flip_char(&acm->port, 0, TTY_BREAK);
+		}
 		if (newctrl & ACM_CTRL_RI)
 			acm->iocount.rng++;
 		if (newctrl & ACM_CTRL_FRAMING)
@@ -378,21 +393,19 @@
 	if (current_size < expected_size) {
 		/* notification is transmitted fragmented, reassemble */
 		if (acm->nb_size < expected_size) {
-			if (acm->nb_size) {
-				kfree(acm->notification_buffer);
-				acm->nb_size = 0;
-			}
+			u8 *new_buffer;
 			alloc_size = roundup_pow_of_two(expected_size);
-			/*
-			 * kmalloc ensures a valid notification_buffer after a
-			 * use of kfree in case the previous allocation was too
-			 * small. Final freeing is done on disconnect.
-			 */
-			acm->notification_buffer =
-				kmalloc(alloc_size, GFP_ATOMIC);
-			if (!acm->notification_buffer)
+			/* Final freeing is done on disconnect. */
+			new_buffer = krealloc(acm->notification_buffer,
+					      alloc_size, GFP_ATOMIC);
+			if (!new_buffer) {
+				acm->nb_index = 0;
 				goto exit;
+			}
+
+			acm->notification_buffer = new_buffer;
 			acm->nb_size = alloc_size;
+			dr = (struct usb_cdc_notification *)acm->notification_buffer;
 		}
 
 		copy_size = min(current_size,
@@ -412,9 +425,12 @@
 
 exit:
 	retval = usb_submit_urb(urb, GFP_ATOMIC);
-	if (retval && retval != -EPERM)
+	if (retval && retval != -EPERM && retval != -ENODEV)
 		dev_err(&acm->control->dev,
 			"%s - usb_submit_urb failed: %d\n", __func__, retval);
+	else
+		dev_vdbg(&acm->control->dev,
+			"control resubmission terminated %d\n", retval);
 }
 
 static int acm_submit_read_urb(struct acm *acm, int index, gfp_t mem_flags)
@@ -430,6 +446,8 @@
 			dev_err(&acm->data->dev,
 				"urb %d failed submission with %d\n",
 				index, res);
+		} else {
+			dev_vdbg(&acm->data->dev, "intended failure %d\n", res);
 		}
 		set_bit(index, &acm->read_urbs_free);
 		return res;
@@ -471,15 +489,11 @@
 	int status = urb->status;
 	bool stopped = false;
 	bool stalled = false;
+	bool cooldown = false;
 
 	dev_vdbg(&acm->data->dev, "got urb %d, len %d, status %d\n",
 		rb->index, urb->actual_length, status);
 
-	if (!acm->dev) {
-		dev_dbg(&acm->data->dev, "%s - disconnected\n", __func__);
-		return;
-	}
-
 	switch (status) {
 	case 0:
 		usb_mark_last_busy(acm->dev);
@@ -497,6 +511,15 @@
 			__func__, status);
 		stopped = true;
 		break;
+	case -EOVERFLOW:
+	case -EPROTO:
+		dev_dbg(&acm->data->dev,
+			"%s - cooling babbling device\n", __func__);
+		usb_mark_last_busy(acm->dev);
+		set_bit(rb->index, &acm->urbs_in_error_delay);
+		set_bit(ACM_ERROR_DELAY, &acm->flags);
+		cooldown = true;
+		break;
 	default:
 		dev_dbg(&acm->data->dev,
 			"%s - nonzero urb status received: %d\n",
@@ -518,9 +541,11 @@
 	 */
 	smp_mb__after_atomic();
 
-	if (stopped || stalled) {
+	if (stopped || stalled || cooldown) {
 		if (stalled)
-			schedule_work(&acm->work);
+			schedule_delayed_work(&acm->dwork, 0);
+		else if (cooldown)
+			schedule_delayed_work(&acm->dwork, HZ / 2);
 		return;
 	}
 
@@ -548,23 +573,29 @@
 	acm_write_done(acm, wb);
 	spin_unlock_irqrestore(&acm->write_lock, flags);
 	set_bit(EVENT_TTY_WAKEUP, &acm->flags);
-	schedule_work(&acm->work);
+	schedule_delayed_work(&acm->dwork, 0);
 }
 
 static void acm_softint(struct work_struct *work)
 {
 	int i;
-	struct acm *acm = container_of(work, struct acm, work);
+	struct acm *acm = container_of(work, struct acm, dwork.work);
 
 	if (test_bit(EVENT_RX_STALL, &acm->flags)) {
-		if (!(usb_autopm_get_interface(acm->data))) {
+		smp_mb(); /* against acm_suspend() */
+		if (!acm->susp_count) {
 			for (i = 0; i < acm->rx_buflimit; i++)
 				usb_kill_urb(acm->read_urbs[i]);
 			usb_clear_halt(acm->dev, acm->in);
 			acm_submit_read_urbs(acm, GFP_KERNEL);
-			usb_autopm_put_interface(acm->data);
+			clear_bit(EVENT_RX_STALL, &acm->flags);
 		}
-		clear_bit(EVENT_RX_STALL, &acm->flags);
+	}
+
+	if (test_and_clear_bit(ACM_ERROR_DELAY, &acm->flags)) {
+		for (i = 0; i < acm->rx_buflimit; i++)
+			if (test_and_clear_bit(i, &acm->urbs_in_error_delay))
+				acm_submit_read_urb(acm, i, GFP_KERNEL);
 	}
 
 	if (test_and_clear_bit(EVENT_TTY_WAKEUP, &acm->flags))
@@ -627,7 +658,8 @@
 
 	res = acm_set_control(acm, val);
 	if (res && (acm->ctrl_caps & USB_CDC_CAP_LINE))
-		dev_err(&acm->control->dev, "failed to set dtr/rts\n");
+		/* This is broken in too many devices to spam the logs */
+		dev_dbg(&acm->control->dev, "failed to set dtr/rts\n");
 }
 
 static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
@@ -709,6 +741,7 @@
 	 * Need to grab write_lock to prevent race with resume, but no need to
 	 * hold it due to the tty-port initialised flag.
 	 */
+	acm_poison_urbs(acm);
 	spin_lock_irq(&acm->write_lock);
 	spin_unlock_irq(&acm->write_lock);
 
@@ -725,7 +758,8 @@
 		usb_autopm_put_interface_async(acm->control);
 	}
 
-	acm_kill_urbs(acm);
+	acm_unpoison_urbs(acm);
+
 }
 
 static void acm_tty_cleanup(struct tty_struct *tty)
@@ -894,12 +928,11 @@
 {
 	struct acm *acm = tty->driver_data;
 
-	ss->xmit_fifo_size = acm->writesize;
-	ss->baud_base = le32_to_cpu(acm->line.dwDTERate);
-	ss->close_delay	= acm->port.close_delay / 10;
+	ss->line = acm->minor;
+	ss->close_delay	= jiffies_to_msecs(acm->port.close_delay) / 10;
 	ss->closing_wait = acm->port.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
 				ASYNC_CLOSING_WAIT_NONE :
-				acm->port.closing_wait / 10;
+				jiffies_to_msecs(acm->port.closing_wait) / 10;
 	return 0;
 }
 
@@ -909,9 +942,10 @@
 	unsigned int closing_wait, close_delay;
 	int retval = 0;
 
-	close_delay = ss->close_delay * 10;
+	close_delay = msecs_to_jiffies(ss->close_delay * 10);
 	closing_wait = ss->closing_wait == ASYNC_CLOSING_WAIT_NONE ?
-			ASYNC_CLOSING_WAIT_NONE : ss->closing_wait * 10;
+			ASYNC_CLOSING_WAIT_NONE :
+			msecs_to_jiffies(ss->closing_wait * 10);
 
 	mutex_lock(&acm->port.mutex);
 
@@ -919,8 +953,6 @@
 		if ((close_delay != acm->port.close_delay) ||
 		    (closing_wait != acm->port.closing_wait))
 			retval = -EPERM;
-		else
-			retval = -EOPNOTSUPP;
 	} else {
 		acm->port.close_delay  = close_delay;
 		acm->port.closing_wait = closing_wait;
@@ -1215,9 +1247,21 @@
 			}
 		}
 	} else {
+		int class = -1;
+
 		data_intf_num = union_header->bSlaveInterface0;
 		control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0);
 		data_interface = usb_ifnum_to_if(usb_dev, data_intf_num);
+
+		if (control_interface)
+			class = control_interface->cur_altsetting->desc.bInterfaceClass;
+
+		if (class != USB_CLASS_COMM && class != USB_CLASS_CDC_DATA) {
+			dev_dbg(&intf->dev, "Broken union descriptor, assuming single interface\n");
+			combined_interfaces = 1;
+			control_interface = data_interface = intf;
+			goto look_for_collapsed_interface;
+		}
 	}
 
 	if (!control_interface || !data_interface) {
@@ -1324,7 +1368,7 @@
 	acm->ctrlsize = ctrlsize;
 	acm->readsize = readsize;
 	acm->rx_buflimit = num_rx_buf;
-	INIT_WORK(&acm->work, acm_softint);
+	INIT_DELAYED_WORK(&acm->dwork, acm_softint);
 	init_waitqueue_head(&acm->wioctl);
 	spin_lock_init(&acm->write_lock);
 	spin_lock_init(&acm->read_lock);
@@ -1475,12 +1519,16 @@
 
 	return 0;
 alloc_fail6:
+	if (!acm->combined_interfaces) {
+		/* Clear driver data so that disconnect() returns early. */
+		usb_set_intfdata(data_interface, NULL);
+		usb_driver_release_interface(&acm_driver, data_interface);
+	}
 	if (acm->country_codes) {
 		device_remove_file(&acm->control->dev,
 				&dev_attr_wCountryCodes);
 		device_remove_file(&acm->control->dev,
 				&dev_attr_iCountryCodeRelDate);
-		kfree(acm->country_codes);
 	}
 	device_remove_file(&acm->control->dev, &dev_attr_bmCapabilities);
 alloc_fail5:
@@ -1512,8 +1560,14 @@
 	if (!acm)
 		return;
 
-	mutex_lock(&acm->mutex);
 	acm->disconnected = true;
+	/*
+	 * there is a circular dependency. acm_softint() can resubmit
+	 * the URBs in error handling so we need to block any
+	 * submission right away
+	 */
+	acm_poison_urbs(acm);
+	mutex_lock(&acm->mutex);
 	if (acm->country_codes) {
 		device_remove_file(&acm->control->dev,
 				&dev_attr_wCountryCodes);
@@ -1532,8 +1586,7 @@
 		tty_kref_put(tty);
 	}
 
-	acm_kill_urbs(acm);
-	cancel_work_sync(&acm->work);
+	cancel_delayed_work_sync(&acm->dwork);
 
 	tty_unregister_device(acm_tty_driver, acm->minor);
 
@@ -1574,8 +1627,9 @@
 	if (cnt)
 		return 0;
 
-	acm_kill_urbs(acm);
-	cancel_work_sync(&acm->work);
+	acm_poison_urbs(acm);
+	cancel_delayed_work_sync(&acm->dwork);
+	acm->urbs_in_error_delay = 0;
 
 	return 0;
 }
@@ -1591,6 +1645,8 @@
 	if (--acm->susp_count)
 		goto out;
 
+	acm_unpoison_urbs(acm);
+
 	if (tty_port_initialized(&acm->port)) {
 		rv = usb_submit_urb(acm->ctrlurb, GFP_ATOMIC);
 
@@ -1655,6 +1711,8 @@
 
 static const struct usb_device_id acm_ids[] = {
 	/* quirky and broken devices */
+	{ USB_DEVICE(0x0424, 0x274e), /* Microchip Technology, Inc. (formerly SMSC) */
+	  .driver_info = DISABLE_ECHO, }, /* DISABLE ECHO in termios flag */
 	{ USB_DEVICE(0x076d, 0x0006), /* Denso Cradle CU-321 */
 	.driver_info = NO_UNION_NORMAL, },/* has no union descriptor */
 	{ USB_DEVICE(0x17ef, 0x7000), /* Lenovo USB modem */
@@ -1662,6 +1720,15 @@
 	{ USB_DEVICE(0x0870, 0x0001), /* Metricom GS Modem */
 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
 	},
+	{ USB_DEVICE(0x045b, 0x023c),	/* Renesas USB Download mode */
+	.driver_info = DISABLE_ECHO,	/* Don't echo banner */
+	},
+	{ USB_DEVICE(0x045b, 0x0248),	/* Renesas USB Download mode */
+	.driver_info = DISABLE_ECHO,	/* Don't echo banner */
+	},
+	{ USB_DEVICE(0x045b, 0x024D),	/* Renesas USB Download mode */
+	.driver_info = DISABLE_ECHO,	/* Don't echo banner */
+	},
 	{ USB_DEVICE(0x0e8d, 0x0003), /* FIREFLY, MediaTek Inc; andrey.arapov@gmail.com */
 	.driver_info = NO_UNION_NORMAL, /* has no union descriptor */
 	},
@@ -1854,6 +1921,10 @@
 	{ USB_DEVICE(0x04d8, 0x0083),	/* Bootloader mode */
 	.driver_info = IGNORE_DEVICE,
 	},
+
+	{ USB_DEVICE(0x04d8, 0xf58b),
+	.driver_info = IGNORE_DEVICE,
+	},
 #endif
 
 	/*Samsung phone in firmware update mode */
@@ -1866,6 +1937,17 @@
 	.driver_info = IGNORE_DEVICE,
 	},
 
+	/* Exclude ETAS ES58x */
+	{ USB_DEVICE(0x108c, 0x0159), /* ES581.4 */
+	.driver_info = IGNORE_DEVICE,
+	},
+	{ USB_DEVICE(0x108c, 0x0168), /* ES582.1 */
+	.driver_info = IGNORE_DEVICE,
+	},
+	{ USB_DEVICE(0x108c, 0x0169), /* ES584.1 */
+	.driver_info = IGNORE_DEVICE,
+	},
+
 	{ USB_DEVICE(0x1bc7, 0x0021), /* Telit 3G ACM only composition */
 	.driver_info = SEND_ZERO_PACKET,
 	},
@@ -1873,6 +1955,16 @@
 	.driver_info = SEND_ZERO_PACKET,
 	},
 
+	/* Exclude Goodix Fingerprint Reader */
+	{ USB_DEVICE(0x27c6, 0x5395),
+	.driver_info = IGNORE_DEVICE,
+	},
+
+	/* Exclude Heimann Sensor GmbH USB appset demo */
+	{ USB_DEVICE(0x32a7, 0x0000),
+	.driver_info = IGNORE_DEVICE,
+	},
+
 	/* control interfaces without any protocol set */
 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_ACM,
 		USB_CDC_PROTO_NONE) },
diff --git a/drivers/usb/class/cdc-acm.h b/drivers/usb/class/cdc-acm.h
index ca1c026..b95ff76 100644
--- a/drivers/usb/class/cdc-acm.h
+++ b/drivers/usb/class/cdc-acm.h
@@ -109,8 +109,10 @@
 #		define EVENT_TTY_WAKEUP	0
 #		define EVENT_RX_STALL	1
 #		define ACM_THROTTLED	2
+#		define ACM_ERROR_DELAY	3
+	unsigned long urbs_in_error_delay;		/* these need to be restarted after a delay */
 	struct usb_cdc_line_coding line;		/* bits, stop, parity */
-	struct work_struct work;			/* work queue entry for line discipline waking up */
+	struct delayed_work dwork;		        /* work queue entry for various purposes */
 	unsigned int ctrlin;				/* input control lines (DCD, DSR, RI, break, overruns) */
 	unsigned int ctrlout;				/* output control lines (DTR, RTS) */
 	struct async_icount iocount;			/* counters for control line changes */
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index 70afb2c..de7bb8e 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -58,6 +58,9 @@
 
 #define WDM_MAX			16
 
+/* we cannot wait forever at flush() */
+#define WDM_FLUSH_TIMEOUT	(30 * HZ)
+
 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
 #define WDM_DEFAULT_BUFSIZE	256
 
@@ -151,7 +154,7 @@
 	kfree(desc->outbuf);
 	desc->outbuf = NULL;
 	clear_bit(WDM_IN_USE, &desc->flags);
-	wake_up(&desc->wait);
+	wake_up_all(&desc->wait);
 }
 
 static void wdm_in_callback(struct urb *urb)
@@ -318,12 +321,23 @@
 
 }
 
-static void kill_urbs(struct wdm_device *desc)
+static void poison_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);
+	usb_poison_urb(desc->command);
+	usb_poison_urb(desc->validity);
+	usb_poison_urb(desc->response);
+}
+
+static void unpoison_urbs(struct wdm_device *desc)
+{
+	/*
+	 *  the order here is not essential
+	 *  it is symmetrical just to be nice
+	 */
+	usb_unpoison_urb(desc->response);
+	usb_unpoison_urb(desc->validity);
+	usb_unpoison_urb(desc->command);
 }
 
 static void free_urbs(struct wdm_device *desc)
@@ -393,6 +407,9 @@
 	if (test_bit(WDM_RESETTING, &desc->flags))
 		r = -EIO;
 
+	if (test_bit(WDM_DISCONNECTING, &desc->flags))
+		r = -ENODEV;
+
 	if (r < 0) {
 		rv = r;
 		goto out_free_mem_pm;
@@ -424,6 +441,7 @@
 	if (rv < 0) {
 		desc->outbuf = NULL;
 		clear_bit(WDM_IN_USE, &desc->flags);
+		wake_up_all(&desc->wait); /* for wdm_wait_for_response() */
 		dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
 		rv = usb_translate_errors(rv);
 		goto out_free_mem_pm;
@@ -458,13 +476,23 @@
 	if (!desc->resp_count || !--desc->resp_count)
 		goto out;
 
+	if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
+		rv = -ENODEV;
+		goto out;
+	}
+	if (test_bit(WDM_RESETTING, &desc->flags)) {
+		rv = -EIO;
+		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);
+		if (!test_bit(WDM_DISCONNECTING, &desc->flags))
+			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);
@@ -583,28 +611,58 @@
 	return rv;
 }
 
-static int wdm_flush(struct file *file, fl_owner_t id)
+static int wdm_wait_for_response(struct file *file, long timeout)
 {
 	struct wdm_device *desc = file->private_data;
+	long rv; /* Use long here because (int) MAX_SCHEDULE_TIMEOUT < 0. */
 
-	wait_event(desc->wait,
-			/*
-			 * needs both flags. We cannot do with one
-			 * because resetting it would cause a race
-			 * with write() yet we need to signal
-			 * a disconnect
-			 */
-			!test_bit(WDM_IN_USE, &desc->flags) ||
-			test_bit(WDM_DISCONNECTING, &desc->flags));
+	/*
+	 * Needs both flags. We cannot do with one because resetting it would
+	 * cause a race with write() yet we need to signal a disconnect.
+	 */
+	rv = wait_event_interruptible_timeout(desc->wait,
+			      !test_bit(WDM_IN_USE, &desc->flags) ||
+			      test_bit(WDM_DISCONNECTING, &desc->flags),
+			      timeout);
 
-	/* cannot dereference desc->intf if WDM_DISCONNECTING */
+	/*
+	 * To report the correct error. This is best effort.
+	 * We are inevitably racing with the hardware.
+	 */
 	if (test_bit(WDM_DISCONNECTING, &desc->flags))
 		return -ENODEV;
-	if (desc->werr < 0)
-		dev_err(&desc->intf->dev, "Error in flush path: %d\n",
-			desc->werr);
+	if (!rv)
+		return -EIO;
+	if (rv < 0)
+		return -EINTR;
 
-	return usb_translate_errors(desc->werr);
+	spin_lock_irq(&desc->iuspin);
+	rv = desc->werr;
+	desc->werr = 0;
+	spin_unlock_irq(&desc->iuspin);
+
+	return usb_translate_errors(rv);
+
+}
+
+/*
+ * You need to send a signal when you react to malicious or defective hardware.
+ * Also, don't abort when fsync() returned -EINVAL, for older kernels which do
+ * not implement wdm_flush() will return -EINVAL.
+ */
+static int wdm_fsync(struct file *file, loff_t start, loff_t end, int datasync)
+{
+	return wdm_wait_for_response(file, MAX_SCHEDULE_TIMEOUT);
+}
+
+/*
+ * Same with wdm_fsync(), except it uses finite timeout in order to react to
+ * malicious or defective hardware which ceased communication after close() was
+ * implicitly called due to process termination.
+ */
+static int wdm_flush(struct file *file, fl_owner_t id)
+{
+	return wdm_wait_for_response(file, WDM_FLUSH_TIMEOUT);
 }
 
 static __poll_t wdm_poll(struct file *file, struct poll_table_struct *wait)
@@ -694,11 +752,12 @@
 	if (!desc->count) {
 		if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
 			dev_dbg(&desc->intf->dev, "wdm_release: cleanup\n");
-			kill_urbs(desc);
+			poison_urbs(desc);
 			spin_lock_irq(&desc->iuspin);
 			desc->resp_count = 0;
 			spin_unlock_irq(&desc->iuspin);
 			desc->manage_power(desc->intf, 0);
+			unpoison_urbs(desc);
 		} else {
 			/* must avoid dev_printk here as desc->intf is invalid */
 			pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
@@ -729,6 +788,7 @@
 	.owner =	THIS_MODULE,
 	.read =		wdm_read,
 	.write =	wdm_write,
+	.fsync =	wdm_fsync,
 	.open =		wdm_open,
 	.flush =	wdm_flush,
 	.release =	wdm_release,
@@ -988,7 +1048,7 @@
 	wake_up_all(&desc->wait);
 	mutex_lock(&desc->rlock);
 	mutex_lock(&desc->wlock);
-	kill_urbs(desc);
+	poison_urbs(desc);
 	cancel_work_sync(&desc->rxwork);
 	cancel_work_sync(&desc->service_outs_intr);
 	mutex_unlock(&desc->wlock);
@@ -1031,9 +1091,10 @@
 		set_bit(WDM_SUSPENDING, &desc->flags);
 		spin_unlock_irq(&desc->iuspin);
 		/* callback submits work - order is essential */
-		kill_urbs(desc);
+		poison_urbs(desc);
 		cancel_work_sync(&desc->rxwork);
 		cancel_work_sync(&desc->service_outs_intr);
+		unpoison_urbs(desc);
 	}
 	if (!PMSG_IS_AUTO(message)) {
 		mutex_unlock(&desc->wlock);
@@ -1091,7 +1152,7 @@
 	wake_up_all(&desc->wait);
 	mutex_lock(&desc->rlock);
 	mutex_lock(&desc->wlock);
-	kill_urbs(desc);
+	poison_urbs(desc);
 	cancel_work_sync(&desc->rxwork);
 	cancel_work_sync(&desc->service_outs_intr);
 	return 0;
@@ -1102,6 +1163,7 @@
 	struct wdm_device *desc = wdm_find_device(intf);
 	int rv;
 
+	unpoison_urbs(desc);
 	clear_bit(WDM_OVERFLOW, &desc->flags);
 	clear_bit(WDM_RESETTING, &desc->flags);
 	rv = recover_from_urb_loss(desc);
diff --git a/drivers/usb/class/usblp.c b/drivers/usb/class/usblp.c
index 0d8e3f3..f27b4ae 100644
--- a/drivers/usb/class/usblp.c
+++ b/drivers/usb/class/usblp.c
@@ -274,8 +274,25 @@
 #define usblp_reset(usblp)\
 	usblp_ctrl_msg(usblp, USBLP_REQ_RESET, USB_TYPE_CLASS, USB_DIR_OUT, USB_RECIP_OTHER, 0, NULL, 0)
 
-#define usblp_hp_channel_change_request(usblp, channel, buffer) \
-	usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST, USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE, channel, buffer, 1)
+static int usblp_hp_channel_change_request(struct usblp *usblp, int channel, u8 *new_channel)
+{
+	u8 *buf;
+	int ret;
+
+	buf = kzalloc(1, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = usblp_ctrl_msg(usblp, USBLP_REQ_HP_CHANNEL_CHANGE_REQUEST,
+			USB_TYPE_VENDOR, USB_DIR_IN, USB_RECIP_INTERFACE,
+			channel, buf, 1);
+	if (ret == 0)
+		*new_channel = buf[0];
+
+	kfree(buf);
+
+	return ret;
+}
 
 /*
  * See the description for usblp_select_alts() below for the usage
@@ -468,7 +485,8 @@
 	usb_autopm_put_interface(usblp->intf);
 
 	if (!usblp->present)		/* finish cleanup from disconnect */
-		usblp_cleanup(usblp);
+		usblp_cleanup(usblp);	/* any URBs must be dead */
+
 	mutex_unlock(&usblp_mutex);
 	return 0;
 }
@@ -476,16 +494,24 @@
 /* No kernel lock - fine */
 static __poll_t usblp_poll(struct file *file, struct poll_table_struct *wait)
 {
-	__poll_t ret;
+	struct usblp *usblp = file->private_data;
+	__poll_t ret = 0;
 	unsigned long flags;
 
-	struct usblp *usblp = file->private_data;
 	/* Should we check file->f_mode & FMODE_WRITE before poll_wait()? */
 	poll_wait(file, &usblp->rwait, wait);
 	poll_wait(file, &usblp->wwait, wait);
+
+	mutex_lock(&usblp->mut);
+	if (!usblp->present)
+		ret |= EPOLLHUP;
+	mutex_unlock(&usblp->mut);
+
 	spin_lock_irqsave(&usblp->lock, flags);
-	ret = ((usblp->bidir && usblp->rcomplete) ? EPOLLIN  | EPOLLRDNORM : 0) |
-	   ((usblp->no_paper || usblp->wcomplete) ? EPOLLOUT | EPOLLWRNORM : 0);
+	if (usblp->bidir && usblp->rcomplete)
+		ret |= EPOLLIN  | EPOLLRDNORM;
+	if (usblp->no_paper || usblp->wcomplete)
+		ret |= EPOLLOUT | EPOLLWRNORM;
 	spin_unlock_irqrestore(&usblp->lock, flags);
 	return ret;
 }
@@ -826,6 +852,11 @@
 	if (rv < 0)
 		return rv;
 
+	if (!usblp->present) {
+		count = -ENODEV;
+		goto done;
+	}
+
 	if ((avail = usblp->rstatus) < 0) {
 		printk(KERN_ERR "usblp%d: error %d reading from printer\n",
 		    usblp->minor, (int)avail);
@@ -1306,14 +1337,17 @@
 	if (protocol < USBLP_FIRST_PROTOCOL || protocol > USBLP_LAST_PROTOCOL)
 		return -EINVAL;
 
-	alts = usblp->protocol[protocol].alt_setting;
-	if (alts < 0)
-		return -EINVAL;
-	r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
-	if (r < 0) {
-		printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
-			alts, usblp->ifnum);
-		return r;
+	/* Don't unnecessarily set the interface if there's a single alt. */
+	if (usblp->intf->num_altsetting > 1) {
+		alts = usblp->protocol[protocol].alt_setting;
+		if (alts < 0)
+			return -EINVAL;
+		r = usb_set_interface(usblp->dev, usblp->ifnum, alts);
+		if (r < 0) {
+			printk(KERN_ERR "usblp: can't set desired altsetting %d on interface %d\n",
+				alts, usblp->ifnum);
+			return r;
+		}
 	}
 
 	usblp->bidir = (usblp->protocol[protocol].epread != NULL);
@@ -1375,9 +1409,11 @@
 
 	usblp_unlink_urbs(usblp);
 	mutex_unlock(&usblp->mut);
+	usb_poison_anchored_urbs(&usblp->urbs);
 
 	if (!usblp->used)
 		usblp_cleanup(usblp);
+
 	mutex_unlock(&usblp_mutex);
 }
 
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index dcd7066..3922a6f 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -2285,17 +2285,10 @@
 		dev_err(dev, "overflow with length %d, actual length is %d\n",
 			data->iin_wMaxPacketSize, urb->actual_length);
 		/* fall through */
-	case -ECONNRESET:
-	case -ENOENT:
-	case -ESHUTDOWN:
-	case -EILSEQ:
-	case -ETIME:
-	case -EPIPE:
+	default:
 		/* urb terminated, clean up */
 		dev_dbg(dev, "urb terminated, status: %d\n", status);
 		return;
-	default:
-		dev_err(dev, "unknown status received: %d\n", status);
 	}
 exit:
 	rv = usb_submit_urb(urb, GFP_ATOMIC);