* each time a write urb is dispatched.
* - is decremented each time a "transmit empty" message is received
* by the driver in the data stream.
- * @sem: Semaphore to lock access to this structure when we need to ensure that
+ * @lock: Mutex to lock access to this structure when we need to ensure that
* races don't occur to access bits of it.
* @open_count: The number of uses of the port currently having
* it open, i.e. the reference count.
bool rcv_flush;
bool xmit_flush;
int tx_pending_bytes;
- struct semaphore sem;
+ struct mutex modelock;
int open_count;
char active; /* someone has this device open */
unsigned char *xfer_to_tty_buffer;
wait_queue_head_t wait;
-
__u8 shadowLCR; /* last LCR value received */
__u8 shadowMCR; /* last MCR value received */
char RxHolding;
unsigned short rcv_or_xmit);
static int qt2_boxsetuart(struct usb_serial *serial, unsigned short Uart_Number,
unsigned short default_divisor, unsigned char default_LCR);
-/*static int qt2_write(struct tty_struct *tty, struct usb_serial_port *port,
- const unsigned char *buf, int count);
-static int qt2_tiocmget(struct tty_struct *tty, struct file *file);
-static int qt2_tiocmset(struct tty_struct *tty, struct file *file,
- unsigned int set, unsigned int clear);*/
static int qt2_boxsethw_flowctl(struct usb_serial *serial,
unsigned int UartNumber, bool bSet);
static int qt2_boxsetsw_flowctl(struct usb_serial *serial, __u16 UartNumber,
/* initialise stuff in the structure */
qt2_port->open_count = 0; /* port is not open */
spin_lock_init(&qt2_port->lock);
+ mutex_init(&qt2_port->modelock);
qt2_set_port_private(port, qt2_port);
}
* Finally we need a bulk in URB to use for background reads from the
* device, which will deal with uplink data from the box to host.
*/
- dbg("serial number is %d", port->serial->minor);
dbg("port0 bulk in endpoint is %#.2x", port0->bulk_in_endpointAddress);
dbg("port0 bulk out endpoint is %#.2x",
port0->bulk_out_endpointAddress);
dev_extra->open_ports);
}
-/* called to deliver writes from the next layer up to the device */
+/**
+ * qt2_write - write bytes from the tty layer out to the USB device.
+ * @buf: The data to be written, size at least count.
+ * @count: The number of bytes requested for transmission.
+ * @return The number of bytes actually accepted for transmission to the device.
+ */
static int qt2_write(struct tty_struct *tty, struct usb_serial_port *port,
const unsigned char *buf, int count)
{
__u8 header_array[5]; /* header used to direct writes to the correct
port on the device */
struct quatech2_port *port_extra; /* extra data for this port */
-
int result;
- /* get the parent device of the port */
- serial = port->serial;
+ serial = port->serial; /* get the parent device of the port */
+ port_extra = qt2_get_port_private(port); /* port extra info */
if (serial == NULL)
return -ENODEV;
- dbg("%s(): port %d", __func__, port->number);
+ dbg("%s(): port %d, requested to write %d bytes, %d already pending",
+ __func__, port->number, count, port_extra->tx_pending_bytes);
if (count <= 0) {
dbg("%s(): write request of <= 0 bytes", __func__);
return 0; /* no bytes written */
}
- port_extra = qt2_get_port_private(port);
/* check if the write urb is already in use, i.e. data already being
* sent to this port */
* the maximum we will ever write to the device as 5 bytes less than
* one URB's worth, by reducing the value of the count argument
* appropriately*/
- if (count > port->bulk_out_size - QT2_TX_HEADER_LENGTH)
+ if (count > port->bulk_out_size - QT2_TX_HEADER_LENGTH) {
count = port->bulk_out_size - QT2_TX_HEADER_LENGTH;
+ dbg("%s(): write request bigger than urb, only accepting "
+ "%d bytes", __func__, count);
+ }
/* we must also ensure that the FIFO at the other end can cope with the
* URB we send it, otherwise it will have problems. As above, we can
* restrict the write size by just shrinking count.*/
- if (count > (QT2_FIFO_DEPTH - port_extra->tx_pending_bytes))
+ if (count > (QT2_FIFO_DEPTH - port_extra->tx_pending_bytes)) {
count = QT2_FIFO_DEPTH - port_extra->tx_pending_bytes;
+ dbg("%s(): not enough room in buffer, only accepting %d bytes",
+ __func__, count);
+ }
/* now build the header for transmission */
header_array[0] = 0x1b;
header_array[1] = 0x1b;
result = usb_submit_urb(port->write_urb, GFP_ATOMIC);
if (result) {
/* error couldn't submit urb */
- result = 0;
+ result = 0; /* return 0 as nothing got written */
dbg("%s(): failed submitting write urb, error %d",
__func__, result);
} else {
- port_extra->tx_pending_bytes += (count - QT2_TX_HEADER_LENGTH);
- /*port->fifo_empty_flag = false;
- port->xmit_fifo_room_bytes = FIFO_DEPTH -
- port->xmit_pending_bytes;*/
- result = count;
- dbg("%s(): submitted write urb, returning %d",
- __func__, result);
+ port_extra->tx_pending_bytes += count;
+ result = count; /* return number of bytes written, i.e. count */
+ dbg("%s(): submitted write urb, wrote %d bytes, "
+ "total pending bytes %d",
+ __func__, result, port_extra->tx_pending_bytes);
}
return result;
}
dbg("%s(): port %d, break_value %d", __func__, port->number,
break_value);
- down(&port_extra->sem);
+ mutex_lock(&port_extra->modelock);
if (!port_extra->open_count) {
dbg("%s(): port not open", __func__);
goto exit;
QT2_BREAK_CONTROL, 0x40, break_value,
port->number, NULL, 0, 300);
exit:
- up(&port_extra->sem);
+ mutex_unlock(&port_extra->modelock);
dbg("%s(): exit port %d", __func__, port->number);
}
return;
}
- down(&port_extra->sem); /* lock structure */
+ mutex_lock(&port_extra->modelock); /* lock structure */
if (!port_extra->open_count) {
dbg("%s(): port not open", __func__);
goto exit;
port->throttled = 1;
exit:
- up(&port_extra->sem);
+ mutex_unlock(&port_extra->modelock);
dbg("%s(): port %d: setting port->throttled", __func__, port->number);
return;
}
port_extra = qt2_get_port_private(port);
port0 = serial->port[0]; /* get the first port's device structure */
- down(&port_extra->sem);
+ mutex_lock(&port_extra->modelock);
if (!port_extra->open_count) {
dbg("%s(): port %d not open", __func__, port->number);
goto exit;
}
}
exit:
- up(&port_extra->sem);
+ mutex_unlock(&port_extra->modelock);
dbg("%s(): exit port %d", __func__, port->number);
return;
}
bool escapeflag; /* flag set to true if this loop iteration is
* parsing an escape sequence, rather than
* ordinary data */
-
-
- dbg("%s(): callback running", __func__);
+ dbg("%s(): callback running, active port is %d", __func__,
+ active->number);
if (urb->status) {
/* read didn't go well */
/* single port device, input is already stopped, so we don't
* need any more input data */
dev_extra->ReadBulkStopped = true;
- return;
+ return;
}
/* finally, we are in a situation where we might consider the data
* that is contained within the URB, and what to do about it.
/* active is a usb_serial_port. It has a member port which is a
* tty_port. From this we get a tty_struct pointer which is what we
- * actually wanted, and keep it on tty_st */
+ * actually wanted, and keep it on tty_st */
tty_st = tty_port_tty_get(&active->port);
if (!tty_st) {
dbg("%s - bad tty pointer - exiting", __func__);
return;
}
- dbg("%s(): active port %d, tty_st =0x%p\n", __func__, active->number,
- tty_st);
RxCount = urb->actual_length; /* grab length of data handy */
if (RxCount) {
dbg("%s(): failed resubmitting read urb, error %d",
__func__, result);
} else {
+ dbg("%s() sucessfully resumitted read urb", __func__);
if (tty_st && RxCount) {
/* if some inbound data was processed, then
* we need to push that through the tty layer
/* cribbed from serqt_usb2 driver, but not sure which work needs
* scheduling - port0 or currently active port? */
/* schedule_work(&port->work); */
-
+ dbg("%s() completed", __func__);
return;
}
__func__, urb->status);
return;
}
-
+ /* FIXME What is supposed to be going on here?
+ * does this actually do anything useful, and should it?
+ */
/*port_softint((void *) serial); commented in vendor driver */
schedule_work(&port->work);
dbg("%s(): port %d exit", __func__, port->number);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff