USB: serial: ftd_sio usb: move status check

[mirror_ubuntu-bionic-kernel.git] / drivers / usb / serial / ftdi_sio.c

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 80ccfa13e0b3de879cd227e5164d8985f186072b..fc527de734653260d283062d09e7f20d5f1e3af6 100644 (file)
--- 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;
@@ -1844,11 +1884,6 @@ static void ftdi_write_bulk_callback(struct urb *urb)
 
        dbg("%s - port %d", __func__, port->number);
 
-       if (status) {
-               dbg("nonzero write bulk status received: %d", status);
-               return;
-       }
-
        priv = usb_get_serial_port_data(port);
        if (!priv) {
                dbg("%s - bad port private data pointer - exiting", __func__);
@@ -1859,13 +1894,18 @@ 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;
        priv->tx_outstanding_bytes -= countback;
        spin_unlock_irqrestore(&priv->tx_lock, flags);
 
+       if (status) {
+               dbg("nonzero write bulk status received: %d", status);
+               return;
+       }
+
        usb_serial_port_softint(port);
 } /* ftdi_write_bulk_callback */
 
@@ -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);