TTY/Serial driver fixes for 3.14-rc3

Here are a small number of tty/serial driver fixes to resolve reported
 issues with 3.14-rc and earlier (in the case of the vt bugfix.)  Some of
 these have been tested and reported by a number of people as the tty
 bugfix was pretty commonly hit on some platforms.
 
 All have been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-3.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver fixes from Greg KH:
 "Here are a small number of tty/serial driver fixes to resolve reported
  issues with 3.14-rc and earlier (in the case of the vt bugfix).  Some
  of these have been tested and reported by a number of people as the
  tty bugfix was pretty commonly hit on some platforms.

  All have been in linux-next for a while"

* tag 'tty-3.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  vt: Fix secure clear screen
  serial: 8250: Support XR17V35x fraction divisor
  n_tty: Fix stale echo output
  serial: sirf: fix kernel panic caused by unpaired spinlock
  serial: 8250_pci: unbreak last serial ports on NetMos 9865 cards
  n_tty: Fix poll() when TIME_CHAR and MIN_CHAR == 0
  serial: omap: fix rs485 probe on defered pinctrl
  serial: 8250_dw: fix compilation warning when !CONFIG_PM_SLEEP
  serial: omap-serial: Move info message to probe function
  tty: Set correct tty name in 'active' sysfs attribute
  tty: n_gsm: Fix for modems with brk in modem status control
  drivers/tty/hvc: don't use module_init in non-modular hyp. console code

Documentation/ABI/testing/sysfs-tty

@@ -3,7 +3,8 @@ Date:		Nov 2010
 Contact:	Kay Sievers <kay.sievers@vrfy.org>
 Description:
 		 Shows the list of currently configured
-		 console devices, like 'tty1 ttyS0'.
+		 tty devices used for the console,
+		 like 'tty1 ttyS0'.
 		 The last entry in the file is the active
 		 device connected to /dev/console.
 		 The file supports poll() to detect virtual

drivers/tty/hvc/hvc_opal.c

@@ -255,13 +255,7 @@ static int __init hvc_opal_init(void)
 	/* Register as a vio device to receive callbacks */
 	return platform_driver_register(&hvc_opal_driver);
 }
-module_init(hvc_opal_init);
+device_initcall(hvc_opal_init);
-
-static void __exit hvc_opal_exit(void)
-{
-	platform_driver_unregister(&hvc_opal_driver);
-}
-module_exit(hvc_opal_exit);
 
 static void udbg_opal_putc(char c)
 {

drivers/tty/hvc/hvc_rtas.c

@@ -102,17 +102,7 @@ static int __init hvc_rtas_init(void)
 
 	return 0;
 }
-module_init(hvc_rtas_init);
+device_initcall(hvc_rtas_init);
-
-/* This will tear down the tty portion of the driver */
-static void __exit hvc_rtas_exit(void)
-{
-	/* Really the fun isn't over until the worker thread breaks down and
-	 * the tty cleans up */
-	if (hvc_rtas_dev)
-		hvc_remove(hvc_rtas_dev);
-}
-module_exit(hvc_rtas_exit);
 
 /* This will happen prior to module init.  There is no tty at this time? */
 static int __init hvc_rtas_console_init(void)

drivers/tty/hvc/hvc_udbg.c

@@ -80,14 +80,7 @@ static int __init hvc_udbg_init(void)
 
 	return 0;
 }
-module_init(hvc_udbg_init);
+device_initcall(hvc_udbg_init);
-
-static void __exit hvc_udbg_exit(void)
-{
-	if (hvc_udbg_dev)
-		hvc_remove(hvc_udbg_dev);
-}
-module_exit(hvc_udbg_exit);
 
 static int __init hvc_udbg_console_init(void)
 {

drivers/tty/hvc/hvc_xen.c

@@ -561,18 +561,7 @@ static int __init xen_hvc_init(void)
 #endif
 	return r;
 }
-
+device_initcall(xen_hvc_init);
-static void __exit xen_hvc_fini(void)
-{
-	struct xencons_info *entry, *next;
-
-	if (list_empty(&xenconsoles))
-			return;
-
-	list_for_each_entry_safe(entry, next, &xenconsoles, list) {
-		xen_console_remove(entry);
-	}
-}
 
 static int xen_cons_init(void)
 {
@@ -598,10 +587,6 @@ static int xen_cons_init(void)
 	hvc_instantiate(HVC_COOKIE, 0, ops);
 	return 0;
 }
-
-
-module_init(xen_hvc_init);
-module_exit(xen_hvc_fini);
 console_initcall(xen_cons_init);
 
 #ifdef CONFIG_EARLY_PRINTK

drivers/tty/n_gsm.c

@@ -1090,6 +1090,7 @@ static void gsm_control_modem(struct gsm_mux *gsm, u8 *data, int clen)
 {
 	unsigned int addr = 0;
 	unsigned int modem = 0;
+	unsigned int brk = 0;
 	struct gsm_dlci *dlci;
 	int len = clen;
 	u8 *dp = data;
@@ -1116,6 +1117,16 @@ static void gsm_control_modem(struct gsm_mux *gsm, u8 *data, int clen)
 		if (len == 0)
 			return;
 	}
+	len--;
+	if (len > 0) {
+		while (gsm_read_ea(&brk, *dp++) == 0) {
+			len--;
+			if (len == 0)
+				return;
+		}
+		modem <<= 7;
+		modem |= (brk & 0x7f);
+	}
 	tty = tty_port_tty_get(&dlci->port);
 	gsm_process_modem(tty, dlci, modem, clen);
 	if (tty) {

drivers/tty/n_tty.c

@@ -817,8 +817,7 @@ static void process_echoes(struct tty_struct *tty)
 	struct n_tty_data *ldata = tty->disc_data;
 	size_t echoed;
 
-	if ((!L_ECHO(tty) && !L_ECHONL(tty)) ||
+	if (ldata->echo_mark == ldata->echo_tail)
-	    ldata->echo_mark == ldata->echo_tail)
 		return;
 
 	mutex_lock(&ldata->output_lock);
@@ -1244,7 +1243,8 @@ n_tty_receive_signal_char(struct tty_struct *tty, int signal, unsigned char c)
 	if (L_ECHO(tty)) {
 		echo_char(c, tty);
 		commit_echoes(tty);
-	}
+	} else
+		process_echoes(tty);
 	isig(signal, tty);
 	return;
 }
@@ -1274,7 +1274,7 @@ n_tty_receive_char_special(struct tty_struct *tty, unsigned char c)
 	if (I_IXON(tty)) {
 		if (c == START_CHAR(tty)) {
 			start_tty(tty);
-			commit_echoes(tty);
+			process_echoes(tty);
 			return 0;
 		}
 		if (c == STOP_CHAR(tty)) {
@@ -1820,8 +1820,10 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
 	 * Fix tty hang when I_IXON(tty) is cleared, but the tty
 	 * been stopped by STOP_CHAR(tty) before it.
 	 */
-	if (!I_IXON(tty) && old && (old->c_iflag & IXON) && !tty->flow_stopped)
+	if (!I_IXON(tty) && old && (old->c_iflag & IXON) && !tty->flow_stopped) {
 		start_tty(tty);
+		process_echoes(tty);
+	}
 
 	/* The termios change make the tty ready for I/O */
 	if (waitqueue_active(&tty->write_wait))
@@ -1896,7 +1898,7 @@ err:
 static inline int input_available_p(struct tty_struct *tty, int poll)
 {
 	struct n_tty_data *ldata = tty->disc_data;
-	int amt = poll && !TIME_CHAR(tty) ? MIN_CHAR(tty) : 1;
+	int amt = poll && !TIME_CHAR(tty) && MIN_CHAR(tty) ? MIN_CHAR(tty) : 1;
 
 	if (ldata->icanon && !L_EXTPROC(tty)) {
 		if (ldata->canon_head != ldata->read_tail)

drivers/tty/serial/8250/8250_core.c

@@ -2432,6 +2432,24 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	serial_dl_write(up, quot);
 
+	/*
+	 * XR17V35x UARTs have an extra fractional divisor register (DLD)
+	 *
+	 * We need to recalculate all of the registers, because DLM and DLL
+	 * are already rounded to a whole integer.
+	 *
+	 * When recalculating we use a 32x clock instead of a 16x clock to
+	 * allow 1-bit for rounding in the fractional part.
+	 */
+	if (up->port.type == PORT_XR17V35X) {
+		unsigned int baud_x32 = (port->uartclk * 2) / baud;
+		u16 quot = baud_x32 / 32;
+		u8 quot_frac = DIV_ROUND_CLOSEST(baud_x32 % 32, 2);
+
+		serial_dl_write(up, quot);
+		serial_port_out(port, 0x2, quot_frac & 0xf);
+	}
+
 	/*
 	 * LCR DLAB must be set to enable 64-byte FIFO mode. If the FCR
 	 * is written without DLAB set, this mode will be disabled.

drivers/tty/serial/8250/8250_dw.c

@@ -391,7 +391,7 @@ static int dw8250_remove(struct platform_device *pdev)
 	return 0;
 }
 
-#ifdef CONFIG_PM
+#ifdef CONFIG_PM_SLEEP
 static int dw8250_suspend(struct device *dev)
 {
 	struct dw8250_data *data = dev_get_drvdata(dev);
@@ -409,7 +409,7 @@ static int dw8250_resume(struct device *dev)
 
 	return 0;
 }
-#endif /* CONFIG_PM */
+#endif /* CONFIG_PM_SLEEP */
 
 #ifdef CONFIG_PM_RUNTIME
 static int dw8250_runtime_suspend(struct device *dev)

drivers/tty/serial/8250/8250_pci.c

@@ -783,7 +783,8 @@ static int pci_netmos_9900_setup(struct serial_private *priv,
 {
 	unsigned int bar;
 
-	if ((priv->dev->subsystem_device & 0xff00) == 0x3000) {
+	if ((priv->dev->device != PCI_DEVICE_ID_NETMOS_9865) &&
+	    (priv->dev->subsystem_device & 0xff00) == 0x3000) {
 		/* netmos apparently orders BARs by datasheet layout, so serial
 		 * ports get BARs 0 and 3 (or 1 and 4 for memmapped)
 		 */

drivers/tty/serial/omap-serial.c

@@ -738,9 +738,6 @@ static int serial_omap_startup(struct uart_port *port)
 			return retval;
 		}
 		disable_irq(up->wakeirq);
-	} else {
-		dev_info(up->port.dev, "no wakeirq for uart%d\n",
-			 up->port.line);
 	}
 
 	dev_dbg(up->port.dev, "serial_omap_startup+%d\n", up->port.line);
@@ -1604,8 +1601,11 @@ static int serial_omap_probe_rs485(struct uart_omap_port *up,
 					    flags & SER_RS485_RTS_AFTER_SEND);
 		if (ret < 0)
 			return ret;
-	} else
+	} else if (up->rts_gpio == -EPROBE_DEFER) {
+		return -EPROBE_DEFER;
+	} else {
 		up->rts_gpio = -EINVAL;
+	}
 
 	if (of_property_read_u32_array(np, "rs485-rts-delay",
 				    rs485_delay, 2) == 0) {
@@ -1687,6 +1687,9 @@ static int serial_omap_probe(struct platform_device *pdev)
 	up->port.iotype = UPIO_MEM;
 	up->port.irq = uartirq;
 	up->wakeirq = wakeirq;
+	if (!up->wakeirq)
+		dev_info(up->port.dev, "no wakeirq for uart%d\n",
+			 up->port.line);
 
 	up->port.regshift = 2;
 	up->port.fifosize = 64;

drivers/tty/serial/sirfsoc_uart.c

@@ -542,8 +542,10 @@ static void sirfsoc_rx_tmo_process_tl(unsigned long param)
 	wr_regl(port, ureg->sirfsoc_rx_dma_io_ctrl,
 			rd_regl(port, ureg->sirfsoc_rx_dma_io_ctrl) |
 			SIRFUART_IO_MODE);
-	sirfsoc_uart_pio_rx_chars(port, 4 - sirfport->rx_io_count);
 	spin_unlock_irqrestore(&sirfport->rx_lock, flags);
+	spin_lock(&port->lock);
+	sirfsoc_uart_pio_rx_chars(port, 4 - sirfport->rx_io_count);
+	spin_unlock(&port->lock);
 	if (sirfport->rx_io_count == 4) {
 		spin_lock_irqsave(&sirfport->rx_lock, flags);
 		sirfport->rx_io_count = 0;

drivers/tty/tty_io.c

@@ -1267,16 +1267,17 @@ static void pty_line_name(struct tty_driver *driver, int index, char *p)
  *	@p: output buffer of at least 7 bytes
  *
  *	Generate a name from a driver reference and write it to the output
- *	buffer.
+ *	buffer. Return the number of bytes written.
  *
  *	Locking: None
  */
-static void tty_line_name(struct tty_driver *driver, int index, char *p)
+static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p)
 {
 	if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE)
-		strcpy(p, driver->name);
+		return sprintf(p, "%s", driver->name);
 	else
-		sprintf(p, "%s%d", driver->name, index + driver->name_base);
+		return sprintf(p, "%s%d", driver->name,
+			       index + driver->name_base);
 }
 
 /**
@@ -3545,9 +3546,19 @@ static ssize_t show_cons_active(struct device *dev,
 		if (i >= ARRAY_SIZE(cs))
 			break;
 	}
-	while (i--)
+	while (i--) {
-		count += sprintf(buf + count, "%s%d%c",
+		struct tty_driver *driver;
-				 cs[i]->name, cs[i]->index, i ? ' ':'\n');
+		const char *name = cs[i]->name;
+		int index = cs[i]->index;
+
+		driver = cs[i]->device(cs[i], &index);
+		if (driver) {
+			count += tty_line_name(driver, index, buf + count);
+			count += sprintf(buf + count, "%c", i ? ' ':'\n');
+		} else
+			count += sprintf(buf + count, "%s%d%c",
+					 name, index, i ? ' ':'\n');
+	}
 	console_unlock();
 
 	return count;

drivers/tty/vt/vt.c

@@ -1164,6 +1164,8 @@ static void csi_J(struct vc_data *vc, int vpar)
 			scr_memsetw(vc->vc_screenbuf, vc->vc_video_erase_char,
 				    vc->vc_screenbuf_size >> 1);
 			set_origin(vc);
+			if (CON_IS_VISIBLE(vc))
+				update_screen(vc);
 			/* fall through */
 		case 2: /* erase whole display */
 			count = vc->vc_cols * vc->vc_rows;