Merge tag 'tty-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here's the tty and serial driver patches for 4.2-rc1.

  A number of individual driver updates, some code cleanups, and other
  minor things, full details in the shortlog.

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

* tag 'tty-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (152 commits)
  Doc: serial-rs485.txt: update RS485 driver interface
  Doc: tty.txt: remove mention of the BKL
  MAINTAINERS: tty: add serial docs directory
  serial: sprd: check for NULL after calling devm_clk_get
  serial: 8250_pci: Correct uartclk for xr17v35x expansion chips
  serial: 8250_pci: Add support for 12 port Exar boards
  serial: 8250_uniphier: add bindings document for UniPhier UART
  serial: core: cleanup in uart_get_baud_rate()
  serial: stm32-usart: Add STM32 USART Driver
  tty/serial: kill off set_irq_flags usage
  tty: move linux/gsmmux.h to uapi
  doc: dt: add documentation for nxp,lpc1850-uart
  serial: 8250: add LPC18xx/43xx UART driver
  serial: 8250_uniphier: add UniPhier serial driver
  serial: 8250_dw: support ACPI platforms with integrated DMA engine
  serial: of_serial: check the return value of clk_prepare_enable()
  serial: of_serial: use devm_clk_get() instead of clk_get()
  serial: earlycon: Add support for big-endian MMIO accesses
  serial: sirf: use hrtimer for data rx
  serial: sirf: correct the fifo empty_bit
  ...

1 files changed, 62 insertions, 30 deletions

diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c
index 4a24eb2b0ede..8fe52989b380 100644
--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -108,6 +108,7 @@
 #define CON_DRIVER_FLAG_MODULE 1
 #define CON_DRIVER_FLAG_INIT   2
 #define CON_DRIVER_FLAG_ATTR   4
+#define CON_DRIVER_FLAG_ZOMBIE 8
 
 struct con_driver {
 	const struct consw *con;
@@ -135,6 +136,7 @@ const struct consw *conswitchp;
  */
 #define DEFAULT_BELL_PITCH	750
 #define DEFAULT_BELL_DURATION	(HZ/8)
+#define DEFAULT_CURSOR_BLINK_MS	200
 
 struct vc vc_cons [MAX_NR_CONSOLES];
 
@@ -153,6 +155,7 @@ static int set_vesa_blanking(char __user *p);
 static void set_cursor(struct vc_data *vc);
 static void hide_cursor(struct vc_data *vc);
 static void console_callback(struct work_struct *ignored);
+static void con_driver_unregister_callback(struct work_struct *ignored);
 static void blank_screen_t(unsigned long dummy);
 static void set_palette(struct vc_data *vc);
 
@@ -182,6 +185,7 @@ static int blankinterval = 10*60;
 core_param(consoleblank, blankinterval, int, 0444);
 
 static DECLARE_WORK(console_work, console_callback);
+static DECLARE_WORK(con_driver_unregister_work, con_driver_unregister_callback);
 
 /*
  * fg_console is the current virtual console,
@@ -1590,6 +1594,13 @@ static void setterm_command(struct vc_data *vc)
 		case 15: /* activate the previous console */
 			set_console(last_console);
 			break;
+		case 16: /* set cursor blink duration in msec */
+			if (vc->vc_npar >= 1 && vc->vc_par[1] >= 50 &&
+					vc->vc_par[1] <= USHRT_MAX)
+				vc->vc_cur_blink_ms = vc->vc_par[1];
+			else
+				vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
+			break;
 	}
 }
 
@@ -1717,6 +1728,7 @@ static void reset_terminal(struct vc_data *vc, int do_clear)
 
 	vc->vc_bell_pitch = DEFAULT_BELL_PITCH;
 	vc->vc_bell_duration = DEFAULT_BELL_DURATION;
+	vc->vc_cur_blink_ms = DEFAULT_CURSOR_BLINK_MS;
 
 	gotoxy(vc, 0, 0);
 	save_cur(vc);
@@ -3192,22 +3204,6 @@ err:
 
 
 #ifdef CONFIG_VT_HW_CONSOLE_BINDING
-static int con_is_graphics(const struct consw *csw, int first, int last)
-{
-	int i, retval = 0;
-
-	for (i = first; i <= last; i++) {
-		struct vc_data *vc = vc_cons[i].d;
-
-		if (vc && vc->vc_mode == KD_GRAPHICS) {
-			retval = 1;
-			break;
-		}
-	}
-
-	return retval;
-}
-
 /* unlocked version of unbind_con_driver() */
 int do_unbind_con_driver(const struct consw *csw, int first, int last, int deflt)
 {
@@ -3293,8 +3289,7 @@ static int vt_bind(struct con_driver *con)
 	const struct consw *defcsw = NULL, *csw = NULL;
 	int i, more = 1, first = -1, last = -1, deflt = 0;
 
- 	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE) ||
-	    con_is_graphics(con->con, con->first, con->last))
+ 	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
 		goto err;
 
 	csw = con->con;
@@ -3345,8 +3340,7 @@ static int vt_unbind(struct con_driver *con)
 	int i, more = 1, first = -1, last = -1, deflt = 0;
 	int ret;
 
- 	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE) ||
-	    con_is_graphics(con->con, con->first, con->last))
+ 	if (!con->con || !(con->flag & CON_DRIVER_FLAG_MODULE))
 		goto err;
 
 	csw = con->con;
@@ -3596,7 +3590,8 @@ static int do_register_con_driver(const struct consw *csw, int first, int last)
 	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
 		con_driver = &registered_con_driver[i];
 
-		if (con_driver->con == NULL) {
+		if (con_driver->con == NULL &&
+		    !(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE)) {
 			con_driver->con = csw;
 			con_driver->desc = desc;
 			con_driver->node = i;
@@ -3658,16 +3653,20 @@ int do_unregister_con_driver(const struct consw *csw)
 		struct con_driver *con_driver = &registered_con_driver[i];
 
 		if (con_driver->con == csw) {
-			vtconsole_deinit_device(con_driver);
-			device_destroy(vtconsole_class,
-				       MKDEV(0, con_driver->node));
+			/*
+			 * Defer the removal of the sysfs entries since that
+			 * will acquire the kernfs s_active lock and we can't
+			 * acquire this lock while holding the console lock:
+			 * the unbind sysfs entry imposes already the opposite
+			 * order. Reset con already here to prevent any later
+			 * lookup to succeed and mark this slot as zombie, so
+			 * it won't get reused until we complete the removal
+			 * in the deferred work.
+			 */
 			con_driver->con = NULL;
-			con_driver->desc = NULL;
-			con_driver->dev = NULL;
-			con_driver->node = 0;
-			con_driver->flag = 0;
-			con_driver->first = 0;
-			con_driver->last = 0;
+			con_driver->flag = CON_DRIVER_FLAG_ZOMBIE;
+			schedule_work(&con_driver_unregister_work);
+
 			return 0;
 		}
 	}
@@ -3676,6 +3675,39 @@ int do_unregister_con_driver(const struct consw *csw)
 }
 EXPORT_SYMBOL_GPL(do_unregister_con_driver);
 
+static void con_driver_unregister_callback(struct work_struct *ignored)
+{
+	int i;
+
+	console_lock();
+
+	for (i = 0; i < MAX_NR_CON_DRIVER; i++) {
+		struct con_driver *con_driver = &registered_con_driver[i];
+
+		if (!(con_driver->flag & CON_DRIVER_FLAG_ZOMBIE))
+			continue;
+
+		console_unlock();
+
+		vtconsole_deinit_device(con_driver);
+		device_destroy(vtconsole_class, MKDEV(0, con_driver->node));
+
+		console_lock();
+
+		if (WARN_ON_ONCE(con_driver->con))
+			con_driver->con = NULL;
+		con_driver->desc = NULL;
+		con_driver->dev = NULL;
+		con_driver->node = 0;
+		WARN_ON_ONCE(con_driver->flag != CON_DRIVER_FLAG_ZOMBIE);
+		con_driver->flag = 0;
+		con_driver->first = 0;
+		con_driver->last = 0;
+	}
+
+	console_unlock();
+}
+
 /*
  *	If we support more console drivers, this function is used
  *	when a driver wants to take over some existing consoles