Commit f81c83db authored by Bill Pemberton's avatar Bill Pemberton Committed by Greg Kroah-Hartman
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USB: ssu100: rework logic for TIOCMIWAIT 



Rework the logic for TIOCMIWAIT to use wait_event_interruptible.

This also adds support for TIOCGICOUNT.

Signed-off-by: default avatarBill Pemberton <wfp5p@virginia.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 556f1a0e

drivers/usb/serial/ssu100.c

+111 −35
Original line number Diff line number Diff line
@@ -80,6 +80,7 @@ struct ssu100_port_private { 
	u8 shadowMSR;

	wait_queue_head_t delta_msr_wait; /* Used for TIOCMIWAIT */

	unsigned short max_packet_size;

	struct async_icount icount;

};



static void ssu100_release(struct usb_serial *serial)
@@ -330,11 +331,8 @@ static int ssu100_open(struct tty_struct *tty, struct usb_serial_port *port) 
	}



	spin_lock_irqsave(&priv->status_lock, flags);

	priv->shadowLSR = data[0]  & (UART_LSR_OE | UART_LSR_PE |

				      UART_LSR_FE | UART_LSR_BI);



	priv->shadowMSR = data[1]  & (UART_MSR_CTS | UART_MSR_DSR |

				      UART_MSR_RI | UART_MSR_DCD);

	priv->shadowLSR = data[0];

	priv->shadowMSR = data[1];

	spin_unlock_irqrestore(&priv->status_lock, flags);



	kfree(data);
@@ -379,11 +377,51 @@ static int get_serial_info(struct usb_serial_port *port, 
	return 0;

}



static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)

{

	struct ssu100_port_private *priv = usb_get_serial_port_data(port);

	struct async_icount prev, cur;

	unsigned long flags;



	spin_lock_irqsave(&priv->status_lock, flags);

	prev = priv->icount;

	spin_unlock_irqrestore(&priv->status_lock, flags);



	while (1) {

		wait_event_interruptible(priv->delta_msr_wait,

					 ((priv->icount.rng != prev.rng) ||

					  (priv->icount.dsr != prev.dsr) ||

					  (priv->icount.dcd != prev.dcd) ||

					  (priv->icount.cts != prev.cts)));



		if (signal_pending(current))

			return -ERESTARTSYS;



		spin_lock_irqsave(&priv->status_lock, flags);

		cur = priv->icount;

		spin_unlock_irqrestore(&priv->status_lock, flags);



		if ((prev.rng == cur.rng) &&

		    (prev.dsr == cur.dsr) &&

		    (prev.dcd == cur.dcd) &&

		    (prev.cts == cur.cts))

			return -EIO;



		if ((arg & TIOCM_RNG && (prev.rng != cur.rng)) ||

		    (arg & TIOCM_DSR && (prev.dsr != cur.dsr)) ||

		    (arg & TIOCM_CD  && (prev.dcd != cur.dcd)) ||

		    (arg & TIOCM_CTS && (prev.cts != cur.cts)))

			return 0;

	}

	return 0;

}



static int ssu100_ioctl(struct tty_struct *tty, struct file *file,

		    unsigned int cmd, unsigned long arg)

{

	struct usb_serial_port *port = tty->driver_data;

	struct ssu100_port_private *priv = usb_get_serial_port_data(port);

	void __user *user_arg = (void __user *)arg;



	dbg("%s cmd 0x%04x", __func__, cmd);
@@ -393,28 +431,28 @@ static int ssu100_ioctl(struct tty_struct *tty, struct file *file, 
				       (struct serial_struct __user *) arg);



	case TIOCMIWAIT:

		while (priv != NULL) {

			u8 prevMSR = priv->shadowMSR & SERIAL_MSR_MASK;

			interruptible_sleep_on(&priv->delta_msr_wait);

			/* see if a signal did it */

			if (signal_pending(current))

				return -ERESTARTSYS;

			else {

				u8 diff = (priv->shadowMSR & SERIAL_MSR_MASK) ^ prevMSR;

				if (!diff)

					return -EIO; /* no change => error */



				/* Return 0 if caller wanted to know about

				   these bits */



				if (((arg & TIOCM_RNG) && (diff & UART_MSR_RI)) ||

				    ((arg & TIOCM_DSR) && (diff & UART_MSR_DSR)) ||

				    ((arg & TIOCM_CD) && (diff & UART_MSR_DCD)) ||

				    ((arg & TIOCM_CTS) && (diff & UART_MSR_CTS)))

		return wait_modem_info(port, arg);



	case TIOCGICOUNT:

	{

		struct serial_icounter_struct icount;

		struct async_icount cnow = priv->icount;

		memset(&icount, 0, sizeof(icount));

		icount.cts = cnow.cts;

		icount.dsr = cnow.dsr;

		icount.rng = cnow.rng;

		icount.dcd = cnow.dcd;

		icount.rx = cnow.rx;

		icount.tx = cnow.tx;

		icount.frame = cnow.frame;

		icount.overrun = cnow.overrun;

		icount.parity = cnow.parity;

		icount.brk = cnow.brk;

		icount.buf_overrun = cnow.buf_overrun;

		if (copy_to_user(user_arg, &icount, sizeof(icount)))

			return -EFAULT;

		return 0;

	}

		}

		return 0;



	default:

		break;
@@ -541,6 +579,50 @@ static void ssu100_dtr_rts(struct usb_serial_port *port, int on) 
	mutex_unlock(&port->serial->disc_mutex);

}



static void ssu100_update_msr(struct usb_serial_port *port, u8 msr)

{

	struct ssu100_port_private *priv = usb_get_serial_port_data(port);

	unsigned long flags;



	spin_lock_irqsave(&priv->status_lock, flags);

	priv->shadowMSR = msr;

	spin_unlock_irqrestore(&priv->status_lock, flags);



	if (msr & UART_MSR_ANY_DELTA) {

		/* update input line counters */

		if (msr & UART_MSR_DCTS)

			priv->icount.cts++;

		if (msr & UART_MSR_DDSR)

			priv->icount.dsr++;

		if (msr & UART_MSR_DDCD)

			priv->icount.dcd++;

		if (msr & UART_MSR_TERI)

			priv->icount.rng++;

		wake_up_interruptible(&priv->delta_msr_wait);

	}

}



static void ssu100_update_lsr(struct usb_serial_port *port, u8 lsr)

{

	struct ssu100_port_private *priv = usb_get_serial_port_data(port);

	unsigned long flags;



	spin_lock_irqsave(&priv->status_lock, flags);

	priv->shadowLSR = lsr;

	spin_unlock_irqrestore(&priv->status_lock, flags);



	if (lsr & UART_LSR_BRK_ERROR_BITS) {

		if (lsr & UART_LSR_BI)

			priv->icount.brk++;

		if (lsr & UART_LSR_FE)

			priv->icount.frame++;

		if (lsr & UART_LSR_PE)

			priv->icount.parity++;

		if (lsr & UART_LSR_OE)

			priv->icount.overrun++;

	}

}



static int ssu100_process_packet(struct tty_struct *tty,

				 struct usb_serial_port *port,

				 struct ssu100_port_private *priv,
@@ -556,15 +638,9 @@ static int ssu100_process_packet(struct tty_struct *tty, 
	    (packet[0] == 0x1b) && (packet[1] == 0x1b) &&

	    ((packet[2] == 0x00) || (packet[2] == 0x01))) {

		if (packet[2] == 0x00)

			priv->shadowLSR = packet[3] & (UART_LSR_OE |

						       UART_LSR_PE |

						       UART_LSR_FE |

						       UART_LSR_BI);



		if (packet[2] == 0x01) {

			priv->shadowMSR = packet[3];

			wake_up_interruptible(&priv->delta_msr_wait);

		}

			ssu100_update_lsr(port, packet[3]);

		if (packet[2] == 0x01)

			ssu100_update_msr(port, packet[3]);



		len -= 4;

		ch = packet + 4;