From e8c62103fd5fecc8d2086bae244b32d089892175 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Mon, 30 Nov 2009 13:18:24 +0000 Subject: [PATCH] tty: moxa: split open lock moxa_openlock is used for several situations where we want to handle the case of an ioctl that crosses many ports (not just the open tty), and also cases where an open races a deinit (eg a pci unplug) and we hangup a port before we can cope with that. The non open race cases can use the moxa_lock spinlock. This simplifies sorting out the remaining mess. Signed-off-by: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/char/moxa.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c index d53fac5229bf..63ee3bbc1ce4 100644 --- a/drivers/char/moxa.c +++ b/drivers/char/moxa.c @@ -163,6 +163,7 @@ static struct mon_str moxaLog; static unsigned int moxaFuncTout = HZ / 2; static unsigned int moxaLowWaterChk; static DEFINE_MUTEX(moxa_openlock); +static DEFINE_SPINLOCK(moxa_lock); /* Variables for insmod */ #ifdef MODULE static unsigned long baseaddr[MAX_BOARDS]; @@ -313,22 +314,20 @@ static int moxa_ioctl(struct tty_struct *tty, struct file *file, struct moxa_port *p; unsigned int i, j; - mutex_lock(&moxa_openlock); for (i = 0; i < MAX_BOARDS; i++) { p = moxa_boards[i].ports; for (j = 0; j < MAX_PORTS_PER_BOARD; j++, p++, argm++) { memset(&tmp, 0, sizeof(tmp)); + spin_lock_bh(&moxa_lock); if (moxa_boards[i].ready) { tmp.inq = MoxaPortRxQueue(p); tmp.outq = MoxaPortTxQueue(p); } - if (copy_to_user(argm, &tmp, sizeof(tmp))) { - mutex_unlock(&moxa_openlock); + spin_unlock_bh(&moxa_lock); + if (copy_to_user(argm, &tmp, sizeof(tmp))) return -EFAULT; - } } } - mutex_unlock(&moxa_openlock); break; } case MOXA_GET_OQUEUE: status = MoxaPortTxQueue(ch); @@ -344,16 +343,20 @@ static int moxa_ioctl(struct tty_struct *tty, struct file *file, struct moxa_port *p; unsigned int i, j; - mutex_lock(&moxa_openlock); for (i = 0; i < MAX_BOARDS; i++) { p = moxa_boards[i].ports; for (j = 0; j < MAX_PORTS_PER_BOARD; j++, p++, argm++) { struct tty_struct *ttyp; memset(&tmp, 0, sizeof(tmp)); - if (!moxa_boards[i].ready) + spin_lock_bh(&moxa_lock); + if (!moxa_boards[i].ready) { + spin_unlock_bh(&moxa_lock); goto copy; + } status = MoxaPortLineStatus(p); + spin_unlock_bh(&moxa_lock); + if (status & 1) tmp.cts = 1; if (status & 2) @@ -368,13 +371,10 @@ static int moxa_ioctl(struct tty_struct *tty, struct file *file, tmp.cflag = ttyp->termios->c_cflag; tty_kref_put(tty); copy: - if (copy_to_user(argm, &tmp, sizeof(tmp))) { - mutex_unlock(&moxa_openlock); + if (copy_to_user(argm, &tmp, sizeof(tmp))) return -EFAULT; - } } } - mutex_unlock(&moxa_openlock); break; } case TIOCGSERIAL: @@ -427,7 +427,6 @@ 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); /* * HW init -- 2.39.2