Prev: [PATCH] leds-cobalt-qube.c: use resource_size()
Next: [PATCH 47/58] tty: moxa: Use more tty_port ops
From: Greg Kroah-Hartman on 11 Dec 2009 18:40
From: Alan Cox <alan(a)linux.intel.com>

- 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(a)linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de>
---
drivers/char/moxa.c | 58 ++++++++++++++++++++++-----------------------------
1 files changed, 25 insertions(+), 33 deletions(-)

diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c
index 474d936..7ab720f 100644
--- 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;
--
1.6.5.5

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Pages: 1
Prev: [PATCH] leds-cobalt-qube.c: use resource_size()
Next: [PATCH 47/58] tty: moxa: Use more tty_port ops