diff options
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/serial/ftdi_sio.c | 41 |
1 files changed, 16 insertions, 25 deletions
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c index 9699580331a1..8fe034d2d3e7 100644 --- a/drivers/usb/serial/ftdi_sio.c +++ b/drivers/usb/serial/ftdi_sio.c @@ -2328,6 +2328,8 @@ static int ftdi_ioctl(struct tty_struct *tty, { struct usb_serial_port *port = tty->driver_data; struct ftdi_private *priv = usb_get_serial_port_data(port); + struct async_icount cnow; + struct async_icount cprev; dbg("%s cmd 0x%04x", __func__, cmd); @@ -2347,41 +2349,30 @@ static int ftdi_ioctl(struct tty_struct *tty, * - mask passed in arg for lines of interest * (use |'ed TIOCM_RNG/DSR/CD/CTS for masking) * Caller should use TIOCGICOUNT to see which one it was. - * (except that the driver doesn't support it !) * * This code is borrowed from linux/drivers/char/serial.c */ case TIOCMIWAIT: - while (priv != NULL) { + cprev = priv->icount; + while (1) { interruptible_sleep_on(&priv->delta_msr_wait); /* see if a signal did it */ if (signal_pending(current)) return -ERESTARTSYS; - else { - char diff = priv->diff_status; - - if (diff == 0) - return -EIO; /* no change => error */ - - /* Consume all events */ - priv->diff_status = 0; - - /* Return 0 if caller wanted to know about - these bits */ - if (((arg & TIOCM_RNG) && (diff & FTDI_RS0_RI)) || - ((arg & TIOCM_DSR) && (diff & FTDI_RS0_DSR)) || - ((arg & TIOCM_CD) && (diff & FTDI_RS0_RLSD)) || - ((arg & TIOCM_CTS) && (diff & FTDI_RS0_CTS))) { - return 0; - } - /* - * Otherwise caller can't care less about what - * happened,and so we continue to wait for more - * events. - */ + cnow = priv->icount; + if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr && + cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) + return -EIO; /* no change => error */ + if (((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) || + ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) || + ((arg & TIOCM_CD) && (cnow.dcd != cprev.dcd)) || + ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts))) { + return 0; } + cprev = cnow; } - return 0; + /* not reached */ + break; case TIOCSERGETLSR: return get_lsr_info(port, (struct serial_struct __user *)arg); break; |