Merge tag 'tty-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty and serial updates from Greg KH:
 "Here is the big set of tty/serial driver changes for 6.7-rc1. Included
  in here are:

   - console/vgacon cleanups and removals from Arnd

   - tty core and n_tty cleanups from Jiri

   - lots of 8250 driver updates and cleanups

   - sc16is7xx serial driver updates

   - dt binding updates

   - first set of port lock wrapers from Thomas for the printk fixes
     coming in future releases

   - other small serial and tty core cleanups and updates

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'tty-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (193 commits)
  serdev: Replace custom code with device_match_acpi_handle()
  serdev: Simplify devm_serdev_device_open() function
  serdev: Make use of device_set_node()
  tty: n_gsm: add copyright Siemens Mobility GmbH
  tty: n_gsm: fix race condition in status line change on dead connections
  serial: core: Fix runtime PM handling for pending tx
  vgacon: fix mips/sibyte build regression
  dt-bindings: serial: drop unsupported samsung bindings
  tty: serial: samsung: drop earlycon support for unsupported platforms
  tty: 8250: Add note for PX-835
  tty: 8250: Fix IS-200 PCI ID comment
  tty: 8250: Add Brainboxes Oxford Semiconductor-based quirks
  tty: 8250: Add support for Intashield IX cards
  tty: 8250: Add support for additional Brainboxes PX cards
  tty: 8250: Fix up PX-803/PX-857
  tty: 8250: Fix port count of PX-257
  tty: 8250: Add support for Intashield IS-100
  tty: 8250: Add support for Brainboxes UP cards
  tty: 8250: Add support for additional Brainboxes UC cards
  tty: 8250: Remove UC-257 and UC-431
  ...

2 files changed, 28 insertions, 13 deletions

diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index 98764e740c07..34c01874f45b 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -377,18 +377,21 @@ void xen_console_resume(void)
 #ifdef CONFIG_HVC_XEN_FRONTEND
 static void xencons_disconnect_backend(struct xencons_info *info)
 {
-	if (info->irq > 0)
-		unbind_from_irqhandler(info->irq, NULL);
-	info->irq = 0;
+	if (info->hvc != NULL)
+		hvc_remove(info->hvc);
+	info->hvc = NULL;
+	if (info->irq > 0) {
+		evtchn_put(info->evtchn);
+		info->irq = 0;
+		info->evtchn = 0;
+	}
+	/* evtchn_put() will also close it so this is only an error path */
 	if (info->evtchn > 0)
 		xenbus_free_evtchn(info->xbdev, info->evtchn);
 	info->evtchn = 0;
 	if (info->gntref > 0)
 		gnttab_free_grant_references(info->gntref);
 	info->gntref = 0;
-	if (info->hvc != NULL)
-		hvc_remove(info->hvc);
-	info->hvc = NULL;
 }
 
 static void xencons_free(struct xencons_info *info)
@@ -433,7 +436,7 @@ static int xencons_connect_backend(struct xenbus_device *dev,
 	if (ret)
 		return ret;
 	info->evtchn = evtchn;
-	irq = bind_interdomain_evtchn_to_irq_lateeoi(dev, evtchn);
+	irq = bind_evtchn_to_irq_lateeoi(evtchn);
 	if (irq < 0)
 		return irq;
 	info->irq = irq;
@@ -553,10 +556,23 @@ static void xencons_backend_changed(struct xenbus_device *dev,
 		if (dev->state == XenbusStateClosed)
 			break;
 		fallthrough;	/* Missed the backend's CLOSING state */
-	case XenbusStateClosing:
+	case XenbusStateClosing: {
+		struct xencons_info *info = dev_get_drvdata(&dev->dev);;
+
+		/*
+		 * Don't tear down the evtchn and grant ref before the other
+		 * end has disconnected, but do stop userspace from trying
+		 * to use the device before we allow the backend to close.
+		 */
+		if (info->hvc) {
+			hvc_remove(info->hvc);
+			info->hvc = NULL;
+		}
+
 		xenbus_frontend_closed(dev);
 		break;
 	}
+	}
 }
 
 static const struct xenbus_device_id xencons_ids[] = {
@@ -588,7 +604,7 @@ static int __init xen_hvc_init(void)
 		ops = &dom0_hvc_ops;
 		r = xen_initial_domain_console_init();
 		if (r < 0)
-			return r;
+			goto register_fe;
 		info = vtermno_to_xencons(HVC_COOKIE);
 	} else {
 		ops = &domU_hvc_ops;
@@ -597,7 +613,7 @@ static int __init xen_hvc_init(void)
 		else
 			r = xen_pv_console_init();
 		if (r < 0)
-			return r;
+			goto register_fe;
 
 		info = vtermno_to_xencons(HVC_COOKIE);
 		info->irq = bind_evtchn_to_irq_lateeoi(info->evtchn);
@@ -616,12 +632,13 @@ static int __init xen_hvc_init(void)
 		list_del(&info->list);
 		spin_unlock_irqrestore(&xencons_lock, flags);
 		if (info->irq)
-			unbind_from_irqhandler(info->irq, NULL);
+			evtchn_put(info->evtchn);
 		kfree(info);
 		return r;
 	}
 
 	r = 0;
+ register_fe:
 #ifdef CONFIG_HVC_XEN_FRONTEND
 	r = xenbus_register_frontend(&xencons_driver);
 #endif
diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
index 98433a53bae1..f57fd9095f75 100644
--- a/drivers/tty/hvc/hvcs.c
+++ b/drivers/tty/hvc/hvcs.c
@@ -664,7 +664,6 @@ static void hvcs_return_index(int index)
 static void hvcs_destruct_port(struct tty_port *p)
 {
 	struct hvcs_struct *hvcsd = container_of(p, struct hvcs_struct, port);
-	struct vio_dev *vdev;
 	struct completion *comp;
 	unsigned long flags;
 
@@ -686,7 +685,6 @@ static void hvcs_destruct_port(struct tty_port *p)
 	printk(KERN_INFO "HVCS: Destroyed hvcs_struct for vty-server@%X.\n",
 			hvcsd->vdev->unit_address);
 
-	vdev = hvcsd->vdev;
 	hvcsd->vdev = NULL;
 
 	hvcsd->p_unit_address = 0;