4 files changed, 12 insertions, 4 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index ad38c746270a..7ede29d4c7c1 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1379,6 +1379,8 @@ made_compressed_probe:
 		acm->ctrl_caps = h.usb_cdc_acm_descriptor->bmCapabilities;
 	if (quirks & NO_CAP_LINE)
 		acm->ctrl_caps &= ~USB_CDC_CAP_LINE;
+	if (quirks & MISSING_CAP_BRK)
+		acm->ctrl_caps |= USB_CDC_CAP_BRK;
 	acm->ctrlsize = ctrlsize;
 	acm->readsize = readsize;
 	acm->rx_buflimit = num_rx_buf;
@@ -2002,6 +2004,9 @@ static const struct usb_device_id acm_ids[] = {
 	.driver_info = IGNORE_DEVICE,
 	},
 
+	/* CH343 supports CAP_BRK, but doesn't advertise it */
+	{ USB_DEVICE(0x1a86, 0x55d3), .driver_info = MISSING_CAP_BRK, },
+
 	/* 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 759ac15631d3..76f73853a60b 100644
--- a/drivers/usb/class/cdc-acm.h
+++ b/drivers/usb/class/cdc-acm.h
@@ -113,3 +113,4 @@ struct acm {
 #define CLEAR_HALT_CONDITIONS		BIT(5)
 #define SEND_ZERO_PACKET		BIT(6)
 #define DISABLE_ECHO			BIT(7)
+#define MISSING_CAP_BRK			BIT(8)
diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c
index f2d94cfc70af..7556c0dac908 100644
--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -225,7 +225,8 @@ static void wdm_in_callback(struct urb *urb)
 		/* we may already be in overflow */
 		if (!test_bit(WDM_OVERFLOW, &desc->flags)) {
 			memmove(desc->ubuf + desc->length, desc->inbuf, length);
-			desc->length += length;
+			smp_wmb(); /* against wdm_read() */
+			WRITE_ONCE(desc->length, desc->length + length);
 		}
 	}
 skip_error:
@@ -533,6 +534,7 @@ static ssize_t wdm_read
 		return -ERESTARTSYS;
 
 	cntr = READ_ONCE(desc->length);
+	smp_rmb(); /* against wdm_in_callback() */
 	if (cntr == 0) {
 		desc->read = 0;
 retry:
diff --git a/drivers/usb/class/usbtmc.c b/drivers/usb/class/usbtmc.c
index 2526a0e03cde..d39bbfd7fd18 100644
--- a/drivers/usb/class/usbtmc.c
+++ b/drivers/usb/class/usbtmc.c
@@ -727,7 +727,7 @@ static int usbtmc488_ioctl_trigger(struct usbtmc_file_data *file_data)
 	buffer[1] = data->bTag;
 	buffer[2] = ~data->bTag;
 
-	retval = usb_bulk_msg(data->usb_dev,
+	retval = usb_bulk_msg_killable(data->usb_dev,
 			      usb_sndbulkpipe(data->usb_dev,
 					      data->bulk_out),
 			      buffer, USBTMC_HEADER_SIZE,
@@ -1347,7 +1347,7 @@ static int send_request_dev_dep_msg_in(struct usbtmc_file_data *file_data,
 	buffer[11] = 0; /* Reserved */
 
 	/* Send bulk URB */
-	retval = usb_bulk_msg(data->usb_dev,
+	retval = usb_bulk_msg_killable(data->usb_dev,
 			      usb_sndbulkpipe(data->usb_dev,
 					      data->bulk_out),
 			      buffer, USBTMC_HEADER_SIZE,
@@ -1419,7 +1419,7 @@ static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 	actual = 0;
 
 	/* Send bulk URB */
-	retval = usb_bulk_msg(data->usb_dev,
+	retval = usb_bulk_msg_killable(data->usb_dev,
 			      usb_rcvbulkpipe(data->usb_dev,
 					      data->bulk_in),
 			      buffer, bufsize, &actual,