diff options
| -rw-r--r-- | drivers/usb/serial/generic.c | 121 | ||||
| -rw-r--r-- | drivers/usb/serial/usb_debug.c | 2 | ||||
| -rw-r--r-- | include/linux/usb/serial.h | 4 |
3 files changed, 120 insertions, 7 deletions
diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c index be82ea9..c919686 100644 --- a/drivers/usb/serial/generic.c +++ b/drivers/usb/serial/generic.c @@ -190,6 +190,88 @@ void usb_serial_generic_close(struct usb_serial_port *port) generic_cleanup(port); } +static int usb_serial_multi_urb_write(struct tty_struct *tty, + struct usb_serial_port *port, const unsigned char *buf, int count) +{ + unsigned long flags; + struct urb *urb; + unsigned char *buffer; + int status; + int towrite; + int bwrite = 0; + + dbg("%s - port %d", __func__, port->number); + + if (count == 0) + dbg("%s - write request of 0 bytes", __func__); + + while (count > 0) { + towrite = (count > port->bulk_out_size) ? + port->bulk_out_size : count; + spin_lock_irqsave(&port->lock, flags); + if (port->urbs_in_flight > + port->serial->type->max_in_flight_urbs) { + spin_unlock_irqrestore(&port->lock, flags); + dbg("%s - write limit hit\n", __func__); + return bwrite; + } + port->tx_bytes_flight += towrite; + port->urbs_in_flight++; + spin_unlock_irqrestore(&port->lock, flags); + + buffer = kmalloc(towrite, GFP_ATOMIC); + if (!buffer) { + dev_err(&port->dev, + "%s ran out of kernel memory for urb ...\n", __func__); + goto error_no_buffer; + } + + urb = usb_alloc_urb(0, GFP_ATOMIC); + if (!urb) { + dev_err(&port->dev, "%s - no more free urbs\n", + __func__); + goto error_no_urb; + } + + /* Copy data */ + memcpy(buffer, buf + bwrite, towrite); + usb_serial_debug_data(debug, &port->dev, __func__, + towrite, buffer); + /* fill the buffer and send it */ + usb_fill_bulk_urb(urb, port->serial->dev, + usb_sndbulkpipe(port->serial->dev, + port->bulk_out_endpointAddress), + buffer, towrite, + usb_serial_generic_write_bulk_callback, port); + + status = usb_submit_urb(urb, GFP_ATOMIC); + if (status) { + dev_err(&port->dev, + "%s - failed submitting write urb, error %d\n", + __func__, status); + goto error; + } + + /* This urb is the responsibility of the host driver now */ + usb_free_urb(urb); + dbg("%s write: %d", __func__, towrite); + count -= towrite; + bwrite += towrite; + } + return bwrite; + +error: + usb_free_urb(urb); +error_no_urb: + kfree(buffer); +error_no_buffer: + spin_lock_irqsave(&port->lock, flags); + port->urbs_in_flight--; + port->tx_bytes_flight -= towrite; + spin_unlock_irqrestore(&port->lock, flags); + return bwrite; +} + int usb_serial_generic_write(struct tty_struct *tty, struct usb_serial_port *port, const unsigned char *buf, int count) { @@ -207,6 +289,11 @@ 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); @@ -257,15 +344,18 @@ int usb_serial_generic_write_room(struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; struct usb_serial *serial = port->serial; + unsigned long flags; int room = 0; dbg("%s - port %d", __func__, port->number); - - /* FIXME: Locking */ - if (serial->num_bulk_out) { - if (!(port->write_urb_busy)) + spin_lock_irqsave(&port->lock, flags); + if (serial->type->max_in_flight_urbs) { + if (port->urbs_in_flight < serial->type->max_in_flight_urbs) room = port->bulk_out_size; + } else if (serial->num_bulk_out && !(port->write_urb_busy)) { + room = port->bulk_out_size; } + spin_unlock_irqrestore(&port->lock, flags); dbg("%s - returns %d", __func__, room); return room; @@ -276,11 +366,16 @@ int usb_serial_generic_chars_in_buffer(struct tty_struct *tty) struct usb_serial_port *port = tty->driver_data; struct usb_serial *serial = port->serial; int chars = 0; + unsigned long flags; dbg("%s - port %d", __func__, port->number); - /* FIXME: Locking */ - if (serial->num_bulk_out) { + if (serial->type->max_in_flight_urbs) { + 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; } @@ -363,12 +458,24 @@ EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback); void usb_serial_generic_write_bulk_callback(struct urb *urb) { + unsigned long flags; struct usb_serial_port *port = urb->context; int status = urb->status; dbg("%s - port %d", __func__, port->number); - port->write_urb_busy = 0; + if (port->serial->type->max_in_flight_urbs) { + spin_lock_irqsave(&port->lock, flags); + --port->urbs_in_flight; + port->tx_bytes_flight -= urb->transfer_buffer_length; + if (port->urbs_in_flight < 0) + port->urbs_in_flight = 0; + spin_unlock_irqrestore(&port->lock, flags); + } 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); diff --git a/drivers/usb/serial/usb_debug.c b/drivers/usb/serial/usb_debug.c index 6c9cbb5..a9427a8 100644 --- a/drivers/usb/serial/usb_debug.c +++ b/drivers/usb/serial/usb_debug.c @@ -15,6 +15,7 @@ #include <linux/usb.h> #include <linux/usb/serial.h> +#define URB_DEBUG_MAX_IN_FLIGHT_URBS 4000 #define USB_DEBUG_MAX_PACKET_SIZE 8 static struct usb_device_id id_table [] = { @@ -46,6 +47,7 @@ static struct usb_serial_driver debug_device = { .id_table = id_table, .num_ports = 1, .open = usb_debug_open, + .max_in_flight_urbs = URB_DEBUG_MAX_IN_FLIGHT_URBS, }; static int __init debug_init(void) diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h index 8cdfed7..e2938fd 100644 --- a/include/linux/usb/serial.h +++ b/include/linux/usb/serial.h @@ -91,6 +91,9 @@ struct usb_serial_port { int write_urb_busy; __u8 bulk_out_endpointAddress; + int tx_bytes_flight; + int urbs_in_flight; + wait_queue_head_t write_wait; struct work_struct work; char throttled; @@ -207,6 +210,7 @@ struct usb_serial_driver { struct device_driver driver; struct usb_driver *usb_driver; struct usb_dynids dynids; + int max_in_flight_urbs; int (*probe)(struct usb_serial *serial, const struct usb_device_id *id); int (*attach)(struct usb_serial *serial); |
