diff options
Diffstat (limited to 'drivers/staging/quatech_usb2')
| -rw-r--r-- | drivers/staging/quatech_usb2/quatech_usb2.c | 82 |
1 files changed, 42 insertions, 40 deletions
diff --git a/drivers/staging/quatech_usb2/quatech_usb2.c b/drivers/staging/quatech_usb2/quatech_usb2.c index b06e90d3cef..deb222c7186 100644 --- a/drivers/staging/quatech_usb2/quatech_usb2.c +++ b/drivers/staging/quatech_usb2/quatech_usb2.c @@ -163,7 +163,7 @@ static struct usb_driver quausb2_usb_driver = { * 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. @@ -177,13 +177,12 @@ struct quatech2_port { 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; @@ -263,11 +262,6 @@ static int qt2_box_flush(struct usb_serial *serial, unsigned char uart_number, 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, @@ -356,6 +350,7 @@ static int qt2_attach(struct usb_serial *serial) /* 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); } @@ -535,7 +530,6 @@ int qt2_open(struct tty_struct *tty, struct usb_serial_port *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); @@ -700,7 +694,12 @@ static void qt2_close(struct usb_serial_port *port) 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) { @@ -708,20 +707,19 @@ static int qt2_write(struct tty_struct *tty, struct usb_serial_port *port, __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 */ @@ -747,13 +745,19 @@ static int qt2_write(struct tty_struct *tty, struct usb_serial_port *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; @@ -778,17 +782,15 @@ static int qt2_write(struct tty_struct *tty, struct usb_serial_port *port, 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; } @@ -1178,7 +1180,7 @@ static void qt2_break(struct tty_struct *tty, int break_state) 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; @@ -1188,7 +1190,7 @@ static void qt2_break(struct tty_struct *tty, int break_state) 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); } @@ -1209,7 +1211,7 @@ static void qt2_throttle(struct tty_struct *tty) 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; @@ -1224,7 +1226,7 @@ static void qt2_throttle(struct tty_struct *tty) port->throttled = 1; exit: - up(&port_extra->sem); + mutex_unlock(&port_extra->modelock); dbg("%s(): port %d: setting port->throttled", __func__, port->number); return; } @@ -1251,7 +1253,7 @@ static void qt2_unthrottle(struct tty_struct *tty) 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; @@ -1275,7 +1277,7 @@ static void qt2_unthrottle(struct tty_struct *tty) } } exit: - up(&port_extra->sem); + mutex_unlock(&port_extra->modelock); dbg("%s(): exit port %d", __func__, port->number); return; } @@ -1442,9 +1444,8 @@ static void qt2_read_bulk_callback(struct urb *urb) 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 */ @@ -1502,7 +1503,7 @@ __func__); /* 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. @@ -1512,14 +1513,12 @@ __func__); /* 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) { @@ -1663,6 +1662,7 @@ __func__); 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 @@ -1675,7 +1675,7 @@ __func__); /* 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; } @@ -1699,7 +1699,9 @@ static void qt2_write_bulk_callback(struct urb *urb) __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); |