diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index d9398e9f30ce7ae6ef50f5d867973966e4047079..deba08c7a0151da060ffc66f01a02325da1cbe6b 100644
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -19,7 +19,7 @@
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/uaccess.h>
-
+#include <linux/kfifo.h>
static int debug;
@@ -166,24 +166,6 @@ static void generic_cleanup(struct usb_serial_port *port)
}
}
-int usb_serial_generic_resume(struct usb_serial *serial)
-{
- struct usb_serial_port *port;
- int i, c = 0, r;
-
- for (i = 0; i < serial->num_ports; i++) {
- port = serial->port[i];
- if (port->port.count && port->read_urb) {
- r = usb_submit_urb(port->read_urb, GFP_NOIO);
- if (r < 0)
- c++;
- }
- }
-
- return c ? -EIO : 0;
-}
-EXPORT_SYMBOL_GPL(usb_serial_generic_resume);
-
void usb_serial_generic_close(struct usb_serial_port *port)
{
dbg("%s - port %d", __func__, port->number);
@@ -272,12 +254,81 @@ static int usb_serial_multi_urb_write(struct tty_struct *tty,
return bwrite;
}
+/**
+ * usb_serial_generic_write_start - kick off an URB write
+ * @port: Pointer to the &struct usb_serial_port data
+ *
+ * Returns the number of bytes queued on success. This will be zero if there
+ * was nothing to send. Otherwise, it returns a negative errno value
+ */
+static int usb_serial_generic_write_start(struct usb_serial_port *port)
+{
+ struct usb_serial *serial = port->serial;
+ unsigned char *data;
+ int result;
+ int count;
+ unsigned long flags;
+ bool start_io;
+
+ /* Atomically determine whether we can and need to start a USB
+ * operation. */
+ spin_lock_irqsave(&port->lock, flags);
+ if (port->write_urb_busy)
+ start_io = false;
+ else {
+ start_io = (__kfifo_len(port->write_fifo) != 0);
+ port->write_urb_busy = start_io;
+ }
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ if (!start_io)
+ return 0;
+
+ data = port->write_urb->transfer_buffer;
+ count = kfifo_get(port->write_fifo, data, port->bulk_out_size);
+ usb_serial_debug_data(debug, &port->dev, __func__, count, data);
+
+ /* set up our urb */
+ usb_fill_bulk_urb(port->write_urb, serial->dev,
+ usb_sndbulkpipe(serial->dev,
+ port->bulk_out_endpointAddress),
+ port->write_urb->transfer_buffer, count,
+ ((serial->type->write_bulk_callback) ?
+ serial->type->write_bulk_callback :
+ usb_serial_generic_write_bulk_callback),
+ port);
+
+ /* send the data out the bulk port */
+ result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
+ if (result) {
+ dev_err(&port->dev,
+ "%s - failed submitting write urb, error %d\n",
+ __func__, result);
+ /* don't have to grab the lock here, as we will
+ retry if != 0 */
+ port->write_urb_busy = 0;
+ } else
+ result = count;
+
+ return result;
+}
+
+/**
+ * usb_serial_generic_write - generic write function for serial USB devices
+ * @tty: Pointer to &struct tty_struct for the device
+ * @port: Pointer to the &usb_serial_port structure for the device
+ * @buf: Pointer to the data to write
+ * @count: Number of bytes to write
+ *
+ * Returns the number of characters actually written, which may be anything
+ * from zero to @count. If an error occurs, it returns the negative errno
+ * value.
+ */
int usb_serial_generic_write(struct tty_struct *tty,
struct usb_serial_port *port, const unsigned char *buf, int count)
{
struct usb_serial *serial = port->serial;
int result;
- unsigned char *data;
dbg("%s - port %d", __func__, port->number);
@@ -287,57 +338,20 @@ int usb_serial_generic_write(struct tty_struct *tty,
}
/* only do something if we have a bulk out endpoint */
- if (serial->num_bulk_out) {
- unsigned long flags;
-
- if (serial->type->max_in_flight_urbs)
- return usb_serial_multi_urb_write(tty, port,
- buf, count);
-
- spin_lock_irqsave(&port->lock, flags);
- if (port->write_urb_busy) {
- spin_unlock_irqrestore(&port->lock, flags);
- dbg("%s - already writing", __func__);
- return 0;
- }
- port->write_urb_busy = 1;
- spin_unlock_irqrestore(&port->lock, flags);
-
- count = (count > port->bulk_out_size) ?
- port->bulk_out_size : count;
-
- memcpy(port->write_urb->transfer_buffer, buf, count);
- data = port->write_urb->transfer_buffer;
- usb_serial_debug_data(debug, &port->dev, __func__, count, data);
+ if (!serial->num_bulk_out)
+ return 0;
- /* set up our urb */
- usb_fill_bulk_urb(port->write_urb, serial->dev,
- usb_sndbulkpipe(serial->dev,
- port->bulk_out_endpointAddress),
- port->write_urb->transfer_buffer, count,
- ((serial->type->write_bulk_callback) ?
- serial->type->write_bulk_callback :
- usb_serial_generic_write_bulk_callback),
- port);
+ if (serial->type->max_in_flight_urbs)
+ return usb_serial_multi_urb_write(tty, port,
+ buf, count);
- /* send the data out the bulk port */
- port->write_urb_busy = 1;
- result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
- if (result) {
- dev_err(&port->dev,
- "%s - failed submitting write urb, error %d\n",
- __func__, result);
- /* don't have to grab the lock here, as we will
- retry if != 0 */
- port->write_urb_busy = 0;
- } else
- result = count;
+ count = kfifo_put(port->write_fifo, buf, count);
+ result = usb_serial_generic_write_start(port);
- return result;
- }
+ if (result >= 0)
+ result = count;
- /* no bulk out, so return 0 bytes written */
- return 0;
+ return result;
}
EXPORT_SYMBOL_GPL(usb_serial_generic_write);
@@ -355,9 +369,8 @@ int usb_serial_generic_write_room(struct tty_struct *tty)
room = port->bulk_out_size *
(serial->type->max_in_flight_urbs -
port->urbs_in_flight);
- } else if (serial->num_bulk_out && !(port->write_urb_busy)) {
- room = port->bulk_out_size;
- }
+ } else if (serial->num_bulk_out)
+ room = port->write_fifo->size - __kfifo_len(port->write_fifo);
spin_unlock_irqrestore(&port->lock, flags);
dbg("%s - returns %d", __func__, room);
@@ -377,11 +390,8 @@ int usb_serial_generic_chars_in_buffer(struct tty_struct *tty)
spin_lock_irqsave(&port->lock, flags);
chars = port->tx_bytes_flight;
spin_unlock_irqrestore(&port->lock, flags);
- } else if (serial->num_bulk_out) {
- /* FIXME: Locking */
- if (port->write_urb_busy)
- chars = port->write_urb->transfer_buffer_length;
- }
+ } else if (serial->num_bulk_out)
+ chars = kfifo_len(port->write_fifo);
dbg("%s - returns %d", __func__, chars);
return chars;
@@ -485,16 +495,23 @@ void usb_serial_generic_write_bulk_callback(struct urb *urb)
if (port->urbs_in_flight < 0)
port->urbs_in_flight = 0;
spin_unlock_irqrestore(&port->lock, flags);
+
+ if (status) {
+ dbg("%s - nonzero multi-urb write bulk status "
+ "received: %d", __func__, status);
+ return;
+ }
} else {
- /* Handle the case for single urb mode */
port->write_urb_busy = 0;
- }
- if (status) {
- dbg("%s - nonzero write bulk status received: %d",
- __func__, status);
- return;
+ if (status) {
+ dbg("%s - nonzero multi-urb write bulk status "
+ "received: %d", __func__, status);
+ kfifo_reset(port->write_fifo);
+ } else
+ usb_serial_generic_write_start(port);
}
+
usb_serial_port_softint(port);
}
EXPORT_SYMBOL_GPL(usb_serial_generic_write_bulk_callback);
@@ -559,6 +576,33 @@ int usb_serial_handle_break(struct usb_serial_port *port)
}
EXPORT_SYMBOL_GPL(usb_serial_handle_break);
+int usb_serial_generic_resume(struct usb_serial *serial)
+{
+ struct usb_serial_port *port;
+ int i, c = 0, r;
+
+ for (i = 0; i < serial->num_ports; i++) {
+ port = serial->port[i];
+ if (!port->port.count)
+ continue;
+
+ if (port->read_urb) {
+ r = usb_submit_urb(port->read_urb, GFP_NOIO);
+ if (r < 0)
+ c++;
+ }
+
+ if (port->write_urb) {
+ r = usb_serial_generic_write_start(port);
+ if (r < 0)
+ c++;
+ }
+ }
+
+ return c ? -EIO : 0;
+}
+EXPORT_SYMBOL_GPL(usb_serial_generic_resume);
+
void usb_serial_generic_disconnect(struct usb_serial *serial)
{
int i;
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 45975b4984eabff36729c02d8ef877da1c6508ed..ff75a3589e7e9f809a6839053c20fb2442784d50 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -35,6 +35,7 @@
#include <linux/serial.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
+#include <linux/kfifo.h>
#include "pl2303.h"
/*
@@ -625,6 +626,8 @@ static void port_release(struct device *dev)
usb_free_urb(port->write_urb);
usb_free_urb(port->interrupt_in_urb);
usb_free_urb(port->interrupt_out_urb);
+ if (!IS_ERR(port->write_fifo) && port->write_fifo)
+ kfifo_free(port->write_fifo);
kfree(port->bulk_in_buffer);
kfree(port->bulk_out_buffer);
kfree(port->interrupt_in_buffer);
@@ -964,6 +967,10 @@ int usb_serial_probe(struct usb_interface *interface,
dev_err(&interface->dev, "No free urbs available\n");
goto probe_error;
}
+ port->write_fifo = kfifo_alloc(PAGE_SIZE, GFP_KERNEL,
+ &port->lock);
+ if (IS_ERR(port->write_fifo))
+ goto probe_error;
buffer_size = le16_to_cpu(endpoint->wMaxPacketSize);
port->bulk_out_size = buffer_size;
port->bulk_out_endpointAddress = endpoint->bEndpointAddress;
diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
index 7b85e327af91bfa8a8d15cbc43a2a152f5085a62..c17eb64d721387a44df43c611ddfbc9e8f510daa 100644
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -59,6 +59,7 @@ enum port_dev_state {
* @bulk_out_buffer: pointer to the bulk out buffer for this port.
* @bulk_out_size: the size of the bulk_out_buffer, in bytes.
* @write_urb: pointer to the bulk out struct urb for this port.
+ * @write_fifo: kfifo used to buffer outgoing data
* @write_urb_busy: port`s writing status
* @bulk_out_endpointAddress: endpoint address for the bulk out pipe for this
* port.
@@ -96,6 +97,7 @@ struct usb_serial_port {
unsigned char *bulk_out_buffer;
int bulk_out_size;
struct urb *write_urb;
+ struct kfifo *write_fifo;
int write_urb_busy;
__u8 bulk_out_endpointAddress;