Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934691AbZLKXbu (ORCPT ); Fri, 11 Dec 2009 18:31:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934631AbZLKXb2 (ORCPT ); Fri, 11 Dec 2009 18:31:28 -0500 Received: from kroah.org ([198.145.64.141]:50537 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934485AbZLKX3g (ORCPT ); Fri, 11 Dec 2009 18:29:36 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Alan Cox , Greg Kroah-Hartman Subject: [PATCH 53/58] tty: moxa: split open lock Date: Fri, 11 Dec 2009 15:28:37 -0800 Message-Id: <1260574122-10676-53-git-send-email-gregkh@suse.de> X-Mailer: git-send-email 1.6.5.3 In-Reply-To: <20091211232805.GA10652@kroah.com> References: <20091211232805.GA10652@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3384 Lines: 108 From: Alan Cox 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 files changed, 11 insertions(+), 12 deletions(-) diff --git a/drivers/char/moxa.c b/drivers/char/moxa.c index d53fac5..63ee3bb 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 -- 1.6.5.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/