diff options
| -rw-r--r-- | drivers/usb/serial/ftdi_sio.c | 56 |
1 files changed, 48 insertions, 8 deletions
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index 80ccfa13e0b3..74cc3c831604 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -95,6 +95,7 @@ struct ftdi_private { unsigned long tx_bytes; unsigned long tx_outstanding_bytes; unsigned long tx_outstanding_urbs; + unsigned short max_packet_size; }; /* struct ftdi_sio_quirk is used by devices requiring special attention. */ @@ -703,7 +704,6 @@ static const char *ftdi_chip_name[] = { /* Constants for read urb and write urb */ #define BUFSZ 512 -#define PKTSZ 64 /* rx_flags */ #define THROTTLED 0x01 @@ -1296,6 +1296,45 @@ static void ftdi_determine_type(struct usb_serial_port *port) } +/* Determine the maximum packet size for the device. This depends on the chip + * type and the USB host capabilities. The value should be obtained from the + * device descriptor as the chip will use the appropriate values for the host.*/ +static void ftdi_set_max_packet_size(struct usb_serial_port *port) +{ + struct ftdi_private *priv = usb_get_serial_port_data(port); + struct usb_serial *serial = port->serial; + struct usb_device *udev = serial->dev; + + struct usb_interface *interface = serial->interface; + struct usb_endpoint_descriptor *ep_desc = &interface->cur_altsetting->endpoint[1].desc; + + unsigned num_endpoints; + int i = 0; + + num_endpoints = interface->cur_altsetting->desc.bNumEndpoints; + dev_info(&udev->dev, "Number of endpoints %d\n", num_endpoints); + + /* NOTE: some customers have programmed FT232R/FT245R devices + * with an endpoint size of 0 - not good. In this case, we + * want to override the endpoint descriptor setting and use a + * value of 64 for wMaxPacketSize */ + for (i = 0; i < num_endpoints; i++) { + dev_info(&udev->dev, "Endpoint %d MaxPacketSize %d\n", i+1, + interface->cur_altsetting->endpoint[i].desc.wMaxPacketSize); + ep_desc = &interface->cur_altsetting->endpoint[i].desc; + if (ep_desc->wMaxPacketSize == 0) { + ep_desc->wMaxPacketSize = cpu_to_le16(0x40); + dev_info(&udev->dev, "Overriding wMaxPacketSize on endpoint %d\n", i); + } + } + + /* set max packet size based on descriptor */ + priv->max_packet_size = ep_desc->wMaxPacketSize; + + dev_info(&udev->dev, "Setting MaxPacketSize %d\n", priv->max_packet_size); +} + + /* * *************************************************************************** * Sysfs Attribute @@ -1485,6 +1524,7 @@ static int ftdi_sio_port_probe(struct usb_serial_port *port) usb_set_serial_port_data(port, priv); ftdi_determine_type(port); + ftdi_set_max_packet_size(port); read_latency_timer(port); create_sysfs_attrs(port); return 0; @@ -1740,8 +1780,8 @@ static int ftdi_write(struct tty_struct *tty, struct usb_serial_port *port, if (data_offset > 0) { /* Original sio needs control bytes too... */ transfer_size += (data_offset * - ((count + (PKTSZ - 1 - data_offset)) / - (PKTSZ - data_offset))); + ((count + (priv->max_packet_size - 1 - data_offset)) / + (priv->max_packet_size - data_offset))); } buffer = kmalloc(transfer_size, GFP_ATOMIC); @@ -1763,7 +1803,7 @@ static int ftdi_write(struct tty_struct *tty, struct usb_serial_port *port, if (data_offset > 0) { /* Original sio requires control byte at start of each packet. */ - int user_pktsz = PKTSZ - data_offset; + int user_pktsz = priv->max_packet_size - data_offset; int todo = count; unsigned char *first_byte = buffer; const unsigned char *current_position = buf; @@ -1859,7 +1899,7 @@ static void ftdi_write_bulk_callback(struct urb *urb) data_offset = priv->write_offset; if (data_offset > 0) { /* Subtract the control bytes */ - countback -= (data_offset * DIV_ROUND_UP(countback, PKTSZ)); + countback -= (data_offset * DIV_ROUND_UP(countback, priv->max_packet_size)); } spin_lock_irqsave(&priv->tx_lock, flags); --priv->tx_outstanding_urbs; @@ -1961,7 +2001,7 @@ static void ftdi_read_bulk_callback(struct urb *urb) /* count data bytes, but not status bytes */ countread = urb->actual_length; - countread -= 2 * DIV_ROUND_UP(countread, PKTSZ); + countread -= 2 * DIV_ROUND_UP(countread, priv->max_packet_size); spin_lock_irqsave(&priv->rx_lock, flags); priv->rx_bytes += countread; spin_unlock_irqrestore(&priv->rx_lock, flags); @@ -2034,7 +2074,7 @@ static void ftdi_process_read(struct work_struct *work) need_flip = 0; for (packet_offset = priv->rx_processed; - packet_offset < urb->actual_length; packet_offset += PKTSZ) { + packet_offset < urb->actual_length; packet_offset += priv->max_packet_size) { int length; /* Compare new line status to the old one, signal if different/ @@ -2049,7 +2089,7 @@ static void ftdi_process_read(struct work_struct *work) priv->prev_status = new_status; } - length = min_t(u32, PKTSZ, urb->actual_length-packet_offset)-2; + length = min_t(u32, priv->max_packet_size, urb->actual_length-packet_offset)-2; if (length < 0) { dev_err(&port->dev, "%s - bad packet length: %d\n", __func__, length+2); |