tty: Replace ASYNC_NORMAL_ACTIVE bit and update atomically

Replace ASYNC_NORMAL_ACTIVE bit in the tty_port::flags field with
TTY_PORT_ACTIVE bit in the tty_port::iflags field. Introduce helpers
tty_port_set_active() and tty_port_active() to abstract atomic bit ops.

Extract state changes from port lock sections, as this usage is
broken and confused; the state transitions are protected by the
tty lock (which mutually excludes parallel open/close/hangup),
and no user tests the active state while holding the port lock.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 9 insertions, 11 deletions

diff --git a/drivers/isdn/i4l/isdn_tty.c b/drivers/isdn/i4l/isdn_tty.c
index f1edc0814120..d8468f3529a7 100644
--- a/drivers/isdn/i4l/isdn_tty.c
+++ b/drivers/isdn/i4l/isdn_tty.c
@@ -1622,7 +1622,7 @@ isdn_tty_hangup(struct tty_struct *tty)
 		return;
 	isdn_tty_shutdown(info);
 	port->count = 0;
-	port->flags &= ~ASYNC_NORMAL_ACTIVE;
+	tty_port_set_active(port, 0);
 	port->tty = NULL;
 	wake_up_interruptible(&port->open_wait);
 }
@@ -1979,7 +1979,7 @@ isdn_tty_find_icall(int di, int ch, setup_parm *setup)
 #endif
 			if (
 #ifndef FIX_FILE_TRANSFER
-				(info->port.flags & ASYNC_NORMAL_ACTIVE) &&
+			    tty_port_active(&info->port) &&
 #endif
 				(info->isdn_driver == -1) &&
 				(info->isdn_channel == -1) &&
@@ -2018,8 +2018,6 @@ isdn_tty_find_icall(int di, int ch, setup_parm *setup)
 	return (wret == 2) ? 3 : 0;
 }
 
-#define TTY_IS_ACTIVE(info)	(info->port.flags & ASYNC_NORMAL_ACTIVE)
-
 int
 isdn_tty_stat_callback(int i, isdn_ctrl *c)
 {
@@ -2077,7 +2075,7 @@ isdn_tty_stat_callback(int i, isdn_ctrl *c)
 #ifdef ISDN_TTY_STAT_DEBUG
 			printk(KERN_DEBUG "tty_STAT_DCONN ttyI%d\n", info->line);
 #endif
-			if (TTY_IS_ACTIVE(info)) {
+			if (tty_port_active(&info->port)) {
 				if (info->dialing == 1) {
 					info->dialing = 2;
 					return 1;
@@ -2088,7 +2086,7 @@ isdn_tty_stat_callback(int i, isdn_ctrl *c)
 #ifdef ISDN_TTY_STAT_DEBUG
 			printk(KERN_DEBUG "tty_STAT_DHUP ttyI%d\n", info->line);
 #endif
-			if (TTY_IS_ACTIVE(info)) {
+			if (tty_port_active(&info->port)) {
 				if (info->dialing == 1)
 					isdn_tty_modem_result(RESULT_BUSY, info);
 				if (info->dialing > 1)
@@ -2118,7 +2116,7 @@ isdn_tty_stat_callback(int i, isdn_ctrl *c)
 			 * waiting for it and
 			 * set DCD-bit of its modem-status.
 			 */
-			if (TTY_IS_ACTIVE(info) ||
+			if (tty_port_active(&info->port) ||
 			    (info->port.blocked_open &&
 			     (info->emu.mdmreg[REG_DCD] & BIT_DCD))) {
 				info->msr |= UART_MSR_DCD;
@@ -2145,7 +2143,7 @@ isdn_tty_stat_callback(int i, isdn_ctrl *c)
 #ifdef ISDN_TTY_STAT_DEBUG
 			printk(KERN_DEBUG "tty_STAT_BHUP ttyI%d\n", info->line);
 #endif
-			if (TTY_IS_ACTIVE(info)) {
+			if (tty_port_active(&info->port)) {
 #ifdef ISDN_DEBUG_MODEM_HUP
 				printk(KERN_DEBUG "Mhup in ISDN_STAT_BHUP\n");
 #endif
@@ -2157,7 +2155,7 @@ isdn_tty_stat_callback(int i, isdn_ctrl *c)
 #ifdef ISDN_TTY_STAT_DEBUG
 			printk(KERN_DEBUG "tty_STAT_NODCH ttyI%d\n", info->line);
 #endif
-			if (TTY_IS_ACTIVE(info)) {
+			if (tty_port_active(&info->port)) {
 				if (info->dialing) {
 					info->dialing = 0;
 					info->last_l2 = -1;
@@ -2183,14 +2181,14 @@ isdn_tty_stat_callback(int i, isdn_ctrl *c)
 			return 1;
 #ifdef CONFIG_ISDN_TTY_FAX
 		case ISDN_STAT_FAXIND:
-			if (TTY_IS_ACTIVE(info)) {
+			if (tty_port_active(&info->port)) {
 				isdn_tty_fax_command(info, c);
 			}
 			break;
 #endif
 #ifdef CONFIG_ISDN_AUDIO
 		case ISDN_STAT_AUDIO:
-			if (TTY_IS_ACTIVE(info)) {
+			if (tty_port_active(&info->port)) {
 				switch (c->parm.num[0]) {
 				case ISDN_AUDIO_DTMF:
 					if (info->vonline) {