diff options
| -rw-r--r-- | drivers/usb/serial/generic.c | 132 | ||||
| -rw-r--r-- | include/linux/usb/serial.h | 9 |
2 files changed, 62 insertions, 79 deletions
diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c index be52c748bcc..ad4823bbfa1 100644 --- a/drivers/usb/serial/generic.c +++ b/drivers/usb/serial/generic.c @@ -25,6 +25,8 @@ static int debug; +#define MAX_TX_URBS 40 + #ifdef CONFIG_USB_SERIAL_GENERIC static int generic_probe(struct usb_interface *interface, @@ -172,78 +174,63 @@ static int usb_serial_multi_urb_write(struct tty_struct *tty, 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", __func__); - return bwrite; - } - port->tx_bytes_flight += towrite; - port->urbs_in_flight++; + spin_lock_irqsave(&port->lock, flags); + if (port->tx_urbs == MAX_TX_URBS) { spin_unlock_irqrestore(&port->lock, flags); + dbg("%s - write limit hit", __func__); + return 0; + } + port->tx_urbs++; + 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 free urbs available\n", __func__); + status = -ENOMEM; + goto err_urb; + } - urb = usb_alloc_urb(0, GFP_ATOMIC); - if (!urb) { - dev_err(&port->dev, "%s - no more free urbs\n", + count = min_t(int, count, PAGE_SIZE); + buffer = kmalloc(count, GFP_ATOMIC); + if (!buffer) { + dev_err(&port->dev, "%s - could not allocate buffer\n", __func__); - goto error_no_urb; - } + status = -ENOMEM; + goto err_buf; + } - /* 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, + memcpy(buffer, buf, count); + usb_serial_debug_data(debug, &port->dev, __func__, count, buffer); + usb_fill_bulk_urb(urb, port->serial->dev, usb_sndbulkpipe(port->serial->dev, port->bulk_out_endpointAddress), - buffer, towrite, + buffer, count, port->serial->type->write_bulk_callback, port); - status = usb_submit_urb(urb, GFP_ATOMIC); - if (status) { - dev_err(&port->dev, "%s - error submitting urb: %d\n", + status = usb_submit_urb(urb, GFP_ATOMIC); + if (status) { + dev_err(&port->dev, "%s - error submitting urb: %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; + goto err; } - return bwrite; + spin_lock_irqsave(&port->lock, flags); + port->tx_bytes += urb->transfer_buffer_length; + spin_unlock_irqrestore(&port->lock, flags); -error: usb_free_urb(urb); -error_no_urb: + + return count; +err: kfree(buffer); -error_no_buffer: +err_buf: + usb_free_urb(urb); +err_urb: spin_lock_irqsave(&port->lock, flags); - port->urbs_in_flight--; - port->tx_bytes_flight -= towrite; + port->tx_urbs--; spin_unlock_irqrestore(&port->lock, flags); - return bwrite; + + return status; } /** @@ -286,7 +273,7 @@ static int usb_serial_generic_write_start(struct usb_serial_port *port) } spin_lock_irqsave(&port->lock, flags); - port->tx_bytes_flight += count; + port->tx_bytes += count; spin_unlock_irqrestore(&port->lock, flags); return count; @@ -318,9 +305,8 @@ int usb_serial_generic_write(struct tty_struct *tty, if (!count) return 0; - if (serial->type->max_in_flight_urbs) - return usb_serial_multi_urb_write(tty, port, - buf, count); + if (serial->type->multi_urb_write) + return usb_serial_multi_urb_write(tty, port, buf, count); count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock); result = usb_serial_generic_write_start(port); @@ -337,7 +323,7 @@ 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; + int room; dbg("%s - port %d", __func__, port->number); @@ -345,14 +331,10 @@ int usb_serial_generic_write_room(struct tty_struct *tty) return 0; 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 * - (serial->type->max_in_flight_urbs - - port->urbs_in_flight); - } else { + if (serial->type->multi_urb_write) + room = (MAX_TX_URBS - port->tx_urbs) * PAGE_SIZE; + else room = kfifo_avail(&port->write_fifo); - } spin_unlock_irqrestore(&port->lock, flags); dbg("%s - returns %d", __func__, room); @@ -372,10 +354,10 @@ int usb_serial_generic_chars_in_buffer(struct tty_struct *tty) return 0; spin_lock_irqsave(&port->lock, flags); - if (serial->type->max_in_flight_urbs) - chars = port->tx_bytes_flight; + if (serial->type->multi_urb_write) + chars = port->tx_bytes; else - chars = kfifo_len(&port->write_fifo) + port->tx_bytes_flight; + chars = kfifo_len(&port->write_fifo) + port->tx_bytes; spin_unlock_irqrestore(&port->lock, flags); dbg("%s - returns %d", __func__, chars); @@ -461,18 +443,16 @@ void usb_serial_generic_write_bulk_callback(struct urb *urb) dbg("%s - port %d", __func__, port->number); - if (port->serial->type->max_in_flight_urbs) { + if (port->serial->type->multi_urb_write) { kfree(urb->transfer_buffer); 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; + port->tx_bytes -= urb->transfer_buffer_length; + port->tx_urbs--; spin_unlock_irqrestore(&port->lock, flags); } else { spin_lock_irqsave(&port->lock, flags); - port->tx_bytes_flight -= urb->transfer_buffer_length; + port->tx_bytes -= urb->transfer_buffer_length; port->write_urb_busy = 0; spin_unlock_irqrestore(&port->lock, flags); diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h index ff8872eba3a..2a328376160 100644 --- a/include/linux/usb/serial.h +++ b/include/linux/usb/serial.h @@ -60,6 +60,8 @@ enum port_dev_state { * @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 + * @tx_bytes: number of bytes currently in host stack queues + * @tx_urbs: number of urbs currently in host stack queues * @bulk_out_endpointAddress: endpoint address for the bulk out pipe for this * port. * @write_wait: a wait_queue_head_t used by the port. @@ -98,8 +100,8 @@ struct usb_serial_port { int write_urb_busy; __u8 bulk_out_endpointAddress; - int tx_bytes_flight; - int urbs_in_flight; + int tx_bytes; + int tx_urbs; wait_queue_head_t write_wait; struct work_struct work; @@ -223,7 +225,8 @@ struct usb_serial_driver { struct device_driver driver; struct usb_driver *usb_driver; struct usb_dynids dynids; - int max_in_flight_urbs; + + unsigned char multi_urb_write:1; size_t bulk_in_size; size_t bulk_out_size; |