1 files changed, 31 insertions, 26 deletions

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 23d14b98ae2a..c540de15aad2 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1439,10 +1439,13 @@ static int read_latency_timer(struct usb_serial_port *port)
                              FTDI_SIO_GET_LATENCY_TIMER_REQUEST_TYPE,
                              0, priv->interface,
                              buf, 1, WDR_TIMEOUT);
-        if (rv < 0)
+        if (rv < 1) {
                 dev_err(&port->dev, "Unable to read latency timer: %i\n", rv);
-        else
+                if (rv >= 0)
+                        rv = -EIO;
+        } else {
                 priv->latency = buf[0];
+        }
 
         kfree(buf);
 
@@ -1531,7 +1534,7 @@ check_and_exit:
 }
 
 static int get_lsr_info(struct usb_serial_port *port,
-                        struct serial_struct __user *retinfo)
+                        unsigned int __user *retinfo)
 {
         struct ftdi_private *priv = usb_get_serial_port_data(port);
         unsigned int result = 0;
@@ -1802,8 +1805,6 @@ static int ftdi_sio_port_probe(struct usb_serial_port *port)
 
         mutex_init(&priv->cfg_lock);
 
-        priv->flags = ASYNC_LOW_LATENCY;
-
         if (quirk && quirk->port_probe)
                 quirk->port_probe(priv);
 
@@ -2067,6 +2068,20 @@ static int ftdi_process_packet(struct usb_serial_port *port,
                 priv->prev_status = status;
         }
 
+        /* save if the transmitter is empty or not */
+        if (packet[1] & FTDI_RS_TEMT)
+                priv->transmit_empty = 1;
+        else
+                priv->transmit_empty = 0;
+
+        len -= 2;
+        if (!len)
+                return 0;       /* status only */
+
+        /*
+         * Break and error status must only be processed for packets with
+         * data payload to avoid over-reporting.
+         */
         flag = TTY_NORMAL;
         if (packet[1] & FTDI_RS_ERR_MASK) {
                 /* Break takes precedence over parity, which takes precedence
@@ -2089,15 +2104,6 @@ static int ftdi_process_packet(struct usb_serial_port *port,
                 }
         }
 
-        /* save if the transmitter is empty or not */
-        if (packet[1] & FTDI_RS_TEMT)
-                priv->transmit_empty = 1;
-        else
-                priv->transmit_empty = 0;
-
-        len -= 2;
-        if (!len)
-                return 0;       /* status only */
         port->icount.rx += len;
         ch = packet + 2;
 
@@ -2428,8 +2434,12 @@ static int ftdi_get_modem_status(struct usb_serial_port *port,
                         FTDI_SIO_GET_MODEM_STATUS_REQUEST_TYPE,
                         0, priv->interface,
                         buf, len, WDR_TIMEOUT);
-        if (ret < 0) {
+
+        /* NOTE: We allow short responses and handle that below. */
+        if (ret < 1) {
                 dev_err(&port->dev, "failed to get modem status: %d\n", ret);
+                if (ret >= 0)
+                        ret = -EIO;
                 ret = usb_translate_errors(ret);
                 goto out;
         }
@@ -2480,20 +2490,15 @@ static int ftdi_ioctl(struct tty_struct *tty,
                                         unsigned int cmd, unsigned long arg)
 {
         struct usb_serial_port *port = tty->driver_data;
+        void __user *argp = (void __user *)arg;
 
-        /* Based on code from acm.c and others */
         switch (cmd) {
-
-        case TIOCGSERIAL: /* gets serial port data */
-                return get_serial_info(port,
-                                        (struct serial_struct __user *) arg);
-
-        case TIOCSSERIAL: /* sets serial port data */
-                return set_serial_info(tty, port,
-                                        (struct serial_struct __user *) arg);
+        case TIOCGSERIAL:
+                return get_serial_info(port, argp);
+        case TIOCSSERIAL:
+                return set_serial_info(tty, port, argp);
         case TIOCSERGETLSR:
-                return get_lsr_info(port, (struct serial_struct __user *)arg);
-                break;
+                return get_lsr_info(port, argp);
         default:
                 break;
         }