Commit a808ac0c authored by Alan Cox's avatar Alan Cox Committed by Greg Kroah-Hartman
Browse files

tty: moxa: Locking clean up 



- The open lock is needed to fix up the case of a board reset occuring during
  tty open but too early for a sane hangup response.
- The lock can however got for other cases
- Use the port mutex for get/setserial
- Fix up the confused lack of locking on the THROTTLE and other bits in the
  private flags. Just use set/test/clear bit and it covers the cases we need

Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent f5c5a36d

drivers/char/moxa.c

+25 −33
Original line number Diff line number Diff line
@@ -151,10 +151,10 @@ struct mon_str { 
};



/* statusflags */

#define TXSTOPPED	0x1

#define LOWWAIT 	0x2

#define EMPTYWAIT	0x4

#define THROTTLE	0x8

#define TXSTOPPED	1

#define LOWWAIT 	2

#define EMPTYWAIT	3

#define THROTTLE	4



#define SERIAL_DO_RESTART
@@ -235,6 +235,8 @@ static void MoxaSetFifo(struct moxa_port *port, int enable); 
 * I/O functions

 */



static DEFINE_SPINLOCK(moxafunc_lock);



static void moxa_wait_finish(void __iomem *ofsAddr)

{

	unsigned long end = jiffies + moxaFuncTout;
@@ -381,14 +383,14 @@ copy: 
		break;

	}

	case TIOCGSERIAL:

		mutex_lock(&moxa_openlock);

	        mutex_lock(&ch->port.mutex);

		ret = moxa_get_serial_info(ch, argp);

		mutex_unlock(&moxa_openlock);

		mutex_unlock(&ch->port.mutex);

		break;

	case TIOCSSERIAL:

		mutex_lock(&moxa_openlock);

	        mutex_lock(&ch->port.mutex);

		ret = moxa_set_serial_info(ch, argp);

		mutex_unlock(&moxa_openlock);

		mutex_unlock(&ch->port.mutex);

		break;

	default:

		ret = -ENOIOCTLCMD;
@@ -433,7 +435,6 @@ static const struct tty_port_operations moxa_port_ops = { 
static struct tty_driver *moxaDriver;

static DEFINE_TIMER(moxaTimer, moxa_poll, 0, 0);

static DEFINE_SPINLOCK(moxa_lock);

static DEFINE_SPINLOCK(moxafunc_lock);



/*

 * HW init
@@ -1208,9 +1209,7 @@ static void moxa_close(struct tty_struct *tty, struct file *filp) 
{

	struct moxa_port *ch = tty->driver_data;

	ch->cflag = tty->termios->c_cflag;

	mutex_lock(&moxa_openlock);

	tty_port_close(&ch->port, tty, filp);

	mutex_unlock(&moxa_openlock);

}



static int moxa_write(struct tty_struct *tty,
@@ -1226,7 +1225,7 @@ static int moxa_write(struct tty_struct *tty, 
	len = MoxaPortWriteData(tty, buf, count);

	spin_unlock_bh(&moxa_lock);



	ch->statusflags |= LOWWAIT;

	set_bit(LOWWAIT, &ch->statusflags);

	return len;

}
@@ -1264,7 +1263,7 @@ static int moxa_chars_in_buffer(struct tty_struct *tty) 
		 * Make it possible to wakeup anything waiting for output

		 * in tty_ioctl.c, etc.

		 */

		if (!(ch->statusflags & EMPTYWAIT))

		if (!test_bit(EMPTYWAIT, &ch->statusflags))

			moxa_setup_empty_event(tty);

	}

	unlock_kernel();
@@ -1332,14 +1331,14 @@ static void moxa_throttle(struct tty_struct *tty) 
{

	struct moxa_port *ch = tty->driver_data;



	ch->statusflags |= THROTTLE;

	set_bit(THROTTLE, &ch->statusflags);

}



static void moxa_unthrottle(struct tty_struct *tty)

{

	struct moxa_port *ch = tty->driver_data;



	ch->statusflags &= ~THROTTLE;

	clear_bit(THROTTLE, &ch->statusflags);

}



static void moxa_set_termios(struct tty_struct *tty,
@@ -1361,7 +1360,7 @@ static void moxa_stop(struct tty_struct *tty) 
	if (ch == NULL)

		return;

	MoxaPortTxDisable(ch);

	ch->statusflags |= TXSTOPPED;

	set_bit(TXSTOPPED, &ch->statusflags);

}
@@ -1376,17 +1375,13 @@ static void moxa_start(struct tty_struct *tty) 
		return;



	MoxaPortTxEnable(ch);

	ch->statusflags &= ~TXSTOPPED;

	clear_bit(TXSTOPPED, &ch->statusflags);

}



static void moxa_hangup(struct tty_struct *tty)

{

	struct moxa_port *ch;



	mutex_lock(&moxa_openlock);

	ch = tty->driver_data;

	struct moxa_port *ch = tty->driver_data;

	tty_port_hangup(&ch->port);

	mutex_unlock(&moxa_openlock);

}



static void moxa_new_dcdstate(struct moxa_port *p, u8 dcd)
@@ -1412,24 +1407,24 @@ static int moxa_poll_port(struct moxa_port *p, unsigned int handle, 
	u16 intr;



	if (tty) {

		if ((p->statusflags & EMPTYWAIT) &&

		if (test_bit(EMPTYWAIT, &p->statusflags) &&

				MoxaPortTxQueue(p) == 0) {

			p->statusflags &= ~EMPTYWAIT;

			clear_bit(EMPTYWAIT, &p->statusflags);

			tty_wakeup(tty);

		}

		if ((p->statusflags & LOWWAIT) && !tty->stopped &&

		if (test_bit(LOWWAIT, &p->statusflags) && !tty->stopped &&

				MoxaPortTxQueue(p) <= WAKEUP_CHARS) {

			p->statusflags &= ~LOWWAIT;

			clear_bit(LOWWAIT, &p->statusflags);

			tty_wakeup(tty);

		}



		if (inited && !(p->statusflags & THROTTLE) &&

		if (inited && !test_bit(THROTTLE, &p->statusflags) &&

				MoxaPortRxQueue(p) > 0) { /* RX */

			MoxaPortReadData(p);

			tty_schedule_flip(tty);

		}

	} else {

		p->statusflags &= ~EMPTYWAIT;

		clear_bit(EMPTYWAIT, &p->statusflags);

		MoxaPortFlushData(p, 0); /* flush RX */

	}
@@ -1533,10 +1528,7 @@ static void moxa_set_tty_param(struct tty_struct *tty, struct ktermios *old_term 
static void moxa_setup_empty_event(struct tty_struct *tty)

{

	struct moxa_port *ch = tty->driver_data;



	spin_lock_bh(&moxa_lock);

	ch->statusflags |= EMPTYWAIT;

	spin_unlock_bh(&moxa_lock);

	set_bit(EMPTYWAIT, &ch->statusflags);

}



/*****************************************************************************
@@ -1845,7 +1837,7 @@ static int MoxaPortSetTermio(struct moxa_port *port, struct ktermios *termio, 
		writeb(termio->c_cc[VSTOP], ofsAddr + FuncArg1);

		writeb(FC_SetXonXoff, ofsAddr + FuncCode);

		moxa_wait_finish(ofsAddr);

		spin_unlock_irqrestore(&moxafunc_lock);

		spin_unlock_irq(&moxafunc_lock);



	}

	return baud;

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