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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: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Cox 2009-11-30 13:18:02 +00:00 committed by Greg Kroah-Hartman
parent f5c5a36d27
commit a808ac0c4a
1 changed files with 25 additions and 33 deletions
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58
drivers/char/moxa.c
View File

@ -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;