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>

diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c
index 474d936d3b31935f44fca52262e93a1e3db3f32f..7ab720f1f30ca8e0a50397a3c6d6088763579561 100644 (file)
--- a/drivers/char/moxa.c
+++ b/drivers/char/moxa.c
@@ -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;