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path: root/drivers/usb/serial/ftdi_sio.c
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Diffstat (limited to 'drivers/usb/serial/ftdi_sio.c')
-rw-r--r--drivers/usb/serial/ftdi_sio.c118
1 files changed, 91 insertions, 27 deletions
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 051c3a77b41..3bfcc7b9f86 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -264,7 +264,7 @@
/*
* Version Information
*/
-#define DRIVER_VERSION "v1.4.1"
+#define DRIVER_VERSION "v1.4.2"
#define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Bill Ryder <bryder@sgi.com>, Kuba Ober <kuba@mareimbrium.org>"
#define DRIVER_DESC "USB FTDI Serial Converters Driver"
@@ -687,6 +687,8 @@ struct ftdi_private {
char prev_status, diff_status; /* Used for TIOCMIWAIT */
__u8 rx_flags; /* receive state flags (throttling) */
spinlock_t rx_lock; /* spinlock for receive state */
+ struct work_struct rx_work;
+ int rx_processed;
__u16 interface; /* FT2232C port interface (0 for FT232/245) */
@@ -717,7 +719,7 @@ static int ftdi_write_room (struct usb_serial_port *port);
static int ftdi_chars_in_buffer (struct usb_serial_port *port);
static void ftdi_write_bulk_callback (struct urb *urb, struct pt_regs *regs);
static void ftdi_read_bulk_callback (struct urb *urb, struct pt_regs *regs);
-static void ftdi_process_read (struct usb_serial_port *port);
+static void ftdi_process_read (void *param);
static void ftdi_set_termios (struct usb_serial_port *port, struct termios * old);
static int ftdi_tiocmget (struct usb_serial_port *port, struct file *file);
static int ftdi_tiocmset (struct usb_serial_port *port, struct file * file, unsigned int set, unsigned int clear);
@@ -1387,6 +1389,8 @@ static int ftdi_common_startup (struct usb_serial *serial)
port->read_urb->transfer_buffer_length = BUFSZ;
}
+ INIT_WORK(&priv->rx_work, ftdi_process_read, port);
+
/* Free port's existing write urb and transfer buffer. */
if (port->write_urb) {
usb_free_urb (port->write_urb);
@@ -1617,6 +1621,7 @@ static int ftdi_open (struct usb_serial_port *port, struct file *filp)
spin_unlock_irqrestore(&priv->rx_lock, flags);
/* Start reading from the device */
+ priv->rx_processed = 0;
usb_fill_bulk_urb(port->read_urb, dev,
usb_rcvbulkpipe(dev, port->bulk_in_endpointAddress),
port->read_urb->transfer_buffer, port->read_urb->transfer_buffer_length,
@@ -1667,6 +1672,10 @@ static void ftdi_close (struct usb_serial_port *port, struct file *filp)
err("Error from RTS LOW urb");
}
} /* Note change no line if hupcl is off */
+
+ /* cancel any scheduled reading */
+ cancel_delayed_work(&priv->rx_work);
+ flush_scheduled_work();
/* shutdown our bulk read */
if (port->read_urb)
@@ -1862,23 +1871,14 @@ static void ftdi_read_bulk_callback (struct urb *urb, struct pt_regs *regs)
return;
}
- /* If throttled, delay receive processing until unthrottled. */
- spin_lock(&priv->rx_lock);
- if (priv->rx_flags & THROTTLED) {
- dbg("Deferring read urb processing until unthrottled");
- priv->rx_flags |= ACTUALLY_THROTTLED;
- spin_unlock(&priv->rx_lock);
- return;
- }
- spin_unlock(&priv->rx_lock);
-
ftdi_process_read(port);
} /* ftdi_read_bulk_callback */
-static void ftdi_process_read (struct usb_serial_port *port)
+static void ftdi_process_read (void *param)
{ /* ftdi_process_read */
+ struct usb_serial_port *port = (struct usb_serial_port*)param;
struct urb *urb;
struct tty_struct *tty;
struct ftdi_private *priv;
@@ -1889,6 +1889,7 @@ static void ftdi_process_read (struct usb_serial_port *port)
int result;
int need_flip;
int packet_offset;
+ unsigned long flags;
dbg("%s - port %d", __FUNCTION__, port->number);
@@ -1915,12 +1916,18 @@ static void ftdi_process_read (struct usb_serial_port *port)
data = urb->transfer_buffer;
- /* The first two bytes of every read packet are status */
- if (urb->actual_length > 2) {
- usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
+ if (priv->rx_processed) {
+ dbg("%s - already processed: %d bytes, %d remain", __FUNCTION__,
+ priv->rx_processed,
+ urb->actual_length - priv->rx_processed);
} else {
- dbg("Status only: %03oo %03oo",data[0],data[1]);
- }
+ /* The first two bytes of every read packet are status */
+ if (urb->actual_length > 2) {
+ usb_serial_debug_data(debug, &port->dev, __FUNCTION__, urb->actual_length, data);
+ } else {
+ dbg("Status only: %03oo %03oo",data[0],data[1]);
+ }
+ }
/* TO DO -- check for hung up line and handle appropriately: */
@@ -1929,8 +1936,12 @@ static void ftdi_process_read (struct usb_serial_port *port)
/* if CD is dropped and the line is not CLOCAL then we should hangup */
need_flip = 0;
- for (packet_offset=0; packet_offset < urb->actual_length; packet_offset += PKTSZ) {
+ for (packet_offset = priv->rx_processed; packet_offset < urb->actual_length; packet_offset += PKTSZ) {
+ int length;
+
/* Compare new line status to the old one, signal if different */
+ /* N.B. packet may be processed more than once, but differences
+ * are only processed once. */
if (priv != NULL) {
char new_status = data[packet_offset+0] & FTDI_STATUS_B0_MASK;
if (new_status != priv->prev_status) {
@@ -1940,6 +1951,35 @@ static void ftdi_process_read (struct usb_serial_port *port)
}
}
+ length = min(PKTSZ, urb->actual_length-packet_offset)-2;
+ if (length < 0) {
+ err("%s - bad packet length: %d", __FUNCTION__, length+2);
+ length = 0;
+ }
+
+ /* have to make sure we don't overflow the buffer
+ with tty_insert_flip_char's */
+ if (tty->flip.count+length > TTY_FLIPBUF_SIZE) {
+ tty_flip_buffer_push(tty);
+ need_flip = 0;
+
+ if (tty->flip.count != 0) {
+ /* flip didn't work, this happens when ftdi_process_read() is
+ * called from ftdi_unthrottle, because TTY_DONT_FLIP is set */
+ dbg("%s - flip buffer push failed", __FUNCTION__);
+ break;
+ }
+ }
+ if (priv->rx_flags & THROTTLED) {
+ dbg("%s - throttled", __FUNCTION__);
+ break;
+ }
+ if (tty->ldisc.receive_room(tty)-tty->flip.count < length) {
+ /* break out & wait for throttling/unthrottling to happen */
+ dbg("%s - receive room low", __FUNCTION__);
+ break;
+ }
+
/* Handle errors and break */
error_flag = TTY_NORMAL;
/* Although the device uses a bitmask and hence can have multiple */
@@ -1962,13 +2002,8 @@ static void ftdi_process_read (struct usb_serial_port *port)
error_flag = TTY_FRAME;
dbg("FRAMING error");
}
- if (urb->actual_length > packet_offset + 2) {
- for (i = 2; (i < PKTSZ) && ((i+packet_offset) < urb->actual_length); ++i) {
- /* have to make sure we don't overflow the buffer
- with tty_insert_flip_char's */
- if(tty->flip.count >= TTY_FLIPBUF_SIZE) {
- tty_flip_buffer_push(tty);
- }
+ if (length > 0) {
+ for (i = 2; i < length+2; i++) {
/* Note that the error flag is duplicated for
every character received since we don't know
which character it applied to */
@@ -2005,6 +2040,35 @@ static void ftdi_process_read (struct usb_serial_port *port)
tty_flip_buffer_push(tty);
}
+ if (packet_offset < urb->actual_length) {
+ /* not completely processed - record progress */
+ priv->rx_processed = packet_offset;
+ dbg("%s - incomplete, %d bytes processed, %d remain",
+ __FUNCTION__, packet_offset,
+ urb->actual_length - packet_offset);
+ /* check if we were throttled while processing */
+ spin_lock_irqsave(&priv->rx_lock, flags);
+ if (priv->rx_flags & THROTTLED) {
+ priv->rx_flags |= ACTUALLY_THROTTLED;
+ spin_unlock_irqrestore(&priv->rx_lock, flags);
+ dbg("%s - deferring remainder until unthrottled",
+ __FUNCTION__);
+ return;
+ }
+ spin_unlock_irqrestore(&priv->rx_lock, flags);
+ /* if the port is closed stop trying to read */
+ if (port->open_count > 0){
+ /* delay processing of remainder */
+ schedule_delayed_work(&priv->rx_work, 1);
+ } else {
+ dbg("%s - port is closed", __FUNCTION__);
+ }
+ return;
+ }
+
+ /* urb is completely processed */
+ priv->rx_processed = 0;
+
/* if the port is closed stop trying to read */
if (port->open_count > 0){
/* Continue trying to always read */
@@ -2444,7 +2508,7 @@ static void ftdi_unthrottle (struct usb_serial_port *port)
spin_unlock_irqrestore(&priv->rx_lock, flags);
if (actually_throttled)
- ftdi_process_read(port);
+ schedule_work(&priv->rx_work);
}
static int __init ftdi_init (void)