Merge tag 'tty-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver patches from Greg KH:
 "Here's the big tty/serial driver pull request for 3.12-rc1.

  Lots of n_tty reworks to resolve some very long-standing issues,
  removing the 3-4 different locks that were taken for every character.
  This code has been beaten on for a long time in linux-next with no
  reported regressions.

  Other than that, a range of serial and tty driver updates and
  revisions.  Full details in the shortlog"

* tag 'tty-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (226 commits)
  hvc_xen: Remove unnecessary __GFP_ZERO from kzalloc
  serial: imx: initialize the local variable
  tty: ar933x_uart: add device tree support and binding documentation
  tty: ar933x_uart: allow to build the driver as a module
  ARM: dts: msm: Update uartdm compatible strings
  devicetree: serial: Document msm_serial bindings
  serial: unify serial bindings into a single dir
  serial: fsl-imx-uart: Cleanup duplicate device tree binding
  tty: ar933x_uart: use config_enabled() macro to clean up ifdefs
  tty: ar933x_uart: remove superfluous assignment of ar933x_uart_driver.nr
  tty: ar933x_uart: use the clk API to get the uart clock
  tty: serial: cpm_uart: Adding proper request of GPIO used by cpm_uart driver
  serial: sirf: fix the amount of serial ports
  serial: sirf: define macro for some magic numbers of USP
  serial: icom: move array overflow checks earlier
  TTY: amiserial, remove unnecessary platform_set_drvdata()
  serial: st-asc: remove unnecessary platform_set_drvdata()
  msm_serial: Send more than 1 character on the console w/ UARTDM
  msm_serial: Add support for non-GSBI UARTDM devices
  msm_serial: Switch clock consumer strings and simplify code
  ...

4 files changed, 67 insertions, 17 deletions

diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c
index eb255e807c0..9eba119bcdd 100644
--- a/drivers/tty/hvc/hvc_console.c
+++ b/drivers/tty/hvc/hvc_console.c
@@ -361,7 +361,12 @@ static int hvc_open(struct tty_struct *tty, struct file * filp)
 		tty->driver_data = NULL;
 		tty_port_put(&hp->port);
 		printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc);
-	}
+	} else
+		/* We are ready... raise DTR/RTS */
+		if (C_BAUD(tty))
+			if (hp->ops->dtr_rts)
+				hp->ops->dtr_rts(hp, 1);
+
 	/* Force wakeup of the polling thread */
 	hvc_kick();
 
@@ -393,6 +398,10 @@ static void hvc_close(struct tty_struct *tty, struct file * filp)
 		/* We are done with the tty pointer now. */
 		tty_port_tty_set(&hp->port, NULL);
 
+		if (C_HUPCL(tty))
+			if (hp->ops->dtr_rts)
+				hp->ops->dtr_rts(hp, 0);
+
 		if (hp->ops->notifier_del)
 			hp->ops->notifier_del(hp, hp->data);
 
diff --git a/drivers/tty/hvc/hvc_console.h b/drivers/tty/hvc/hvc_console.h
index 674d23cb919..91310198082 100644
--- a/drivers/tty/hvc/hvc_console.h
+++ b/drivers/tty/hvc/hvc_console.h
@@ -75,6 +75,9 @@ struct hv_ops {
 	/* tiocmget/set implementation */
 	int (*tiocmget)(struct hvc_struct *hp);
 	int (*tiocmset)(struct hvc_struct *hp, unsigned int set, unsigned int clear);
+
+	/* Callbacks to handle tty ports */
+	void (*dtr_rts)(struct hvc_struct *hp, int raise);
 };
 
 /* Register a vterm and a slot index for use as a console (console_init) */
diff --git a/drivers/tty/hvc/hvc_iucv.c b/drivers/tty/hvc/hvc_iucv.c
index 9d47f50c275..fd17a9b804b 100644
--- a/drivers/tty/hvc/hvc_iucv.c
+++ b/drivers/tty/hvc/hvc_iucv.c
@@ -656,21 +656,64 @@ static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id)
 }
 
 /**
+ * hvc_iucv_dtr_rts() - HVC notifier for handling DTR/RTS
+ * @hp:		Pointer the HVC device (struct hvc_struct)
+ * @raise:	Non-zero to raise or zero to lower DTR/RTS lines
+ *
+ * This routine notifies the HVC back-end to raise or lower DTR/RTS
+ * lines.  Raising DTR/RTS is ignored.  Lowering DTR/RTS indicates to
+ * drop the IUCV connection (similar to hang up the modem).
+ */
+static void hvc_iucv_dtr_rts(struct hvc_struct *hp, int raise)
+{
+	struct hvc_iucv_private *priv;
+	struct iucv_path        *path;
+
+	/* Raising the DTR/RTS is ignored as IUCV connections can be
+	 * established at any times.
+	 */
+	if (raise)
+		return;
+
+	priv = hvc_iucv_get_private(hp->vtermno);
+	if (!priv)
+		return;
+
+	/* Lowering the DTR/RTS lines disconnects an established IUCV
+	 * connection.
+	 */
+	flush_sndbuf_sync(priv);
+
+	spin_lock_bh(&priv->lock);
+	path = priv->path;		/* save reference to IUCV path */
+	priv->path = NULL;
+	priv->iucv_state = IUCV_DISCONN;
+	spin_unlock_bh(&priv->lock);
+
+	/* Sever IUCV path outside of priv->lock due to lock ordering of:
+	 * priv->lock <--> iucv_table_lock */
+	if (path) {
+		iucv_path_sever(path, NULL);
+		iucv_path_free(path);
+	}
+}
+
+/**
  * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time.
  * @hp:		Pointer to the HVC device (struct hvc_struct)
  * @id:		Additional data (originally passed to hvc_alloc):
  *		the index of an struct hvc_iucv_private instance.
  *
  * This routine notifies the HVC back-end that the last tty device fd has been
- * closed.  The function calls hvc_iucv_cleanup() to clean up the struct
- * hvc_iucv_private instance.
+ * closed.  The function cleans up tty resources.  The clean-up of the IUCV
+ * connection is done in hvc_iucv_dtr_rts() and depends on the HUPCL termios
+ * control setting.
  *
  * Locking:	struct hvc_iucv_private->lock
  */
 static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id)
 {
 	struct hvc_iucv_private *priv;
-	struct iucv_path	*path;
 
 	priv = hvc_iucv_get_private(id);
 	if (!priv)
@@ -679,17 +722,11 @@ static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id)
 	flush_sndbuf_sync(priv);
 
 	spin_lock_bh(&priv->lock);
-	path = priv->path;		/* save reference to IUCV path */
-	priv->path = NULL;
-	hvc_iucv_cleanup(priv);
+	destroy_tty_buffer_list(&priv->tty_outqueue);
+	destroy_tty_buffer_list(&priv->tty_inqueue);
+	priv->tty_state = TTY_CLOSED;
+	priv->sndbuf_len = 0;
 	spin_unlock_bh(&priv->lock);
-
-	/* sever IUCV path outside of priv->lock due to lock ordering of:
-	 * priv->lock <--> iucv_table_lock */
-	if (path) {
-		iucv_path_sever(path, NULL);
-		iucv_path_free(path);
-	}
 }
 
 /**
@@ -931,6 +968,7 @@ static const struct hv_ops hvc_iucv_ops = {
 	.notifier_add = hvc_iucv_notifier_add,
 	.notifier_del = hvc_iucv_notifier_del,
 	.notifier_hangup = hvc_iucv_notifier_hangup,
+	.dtr_rts = hvc_iucv_dtr_rts,
 };
 
 /* Suspend / resume device operations */
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index 682210d778b..e61c36cbb86 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -208,7 +208,7 @@ static int xen_hvm_console_init(void)
 
 	info = vtermno_to_xencons(HVC_COOKIE);
 	if (!info) {
-		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
+		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
 		if (!info)
 			return -ENOMEM;
 	} else if (info->intf != NULL) {
@@ -257,7 +257,7 @@ static int xen_pv_console_init(void)
 
 	info = vtermno_to_xencons(HVC_COOKIE);
 	if (!info) {
-		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
+		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
 		if (!info)
 			return -ENOMEM;
 	} else if (info->intf != NULL) {
@@ -284,7 +284,7 @@ static int xen_initial_domain_console_init(void)
 
 	info = vtermno_to_xencons(HVC_COOKIE);
 	if (!info) {
-		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL | __GFP_ZERO);
+		info = kzalloc(sizeof(struct xencons_info), GFP_KERNEL);
 		if (!info)
 			return -ENOMEM;
 	}