summary refs log tree commit diff
path: root/drivers/tty
diff options
context:
space:
mode:
authorJiri Kosina <jkosina@suse.cz>2011-07-11 14:15:48 +0200
committerJiri Kosina <jkosina@suse.cz>2011-07-11 14:15:55 +0200
commitb7e9c223be8ce335e30f2cf6ba588e6a4092275c (patch)
tree2d1e3b75606abc18df7ad65e51ac3f90cd68b38d /drivers/tty
parentc172d82500a6cf3c32d1e650722a1055d72ce858 (diff)
parente3bbfa78bab125f58b831b5f7f45b5a305091d72 (diff)
downloadlinux-b7e9c223be8ce335e30f2cf6ba588e6a4092275c.tar.gz
Merge branch 'master' into for-next
Sync with Linus' tree to be able to apply pending patches that
are based on newer code already present upstream.
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/n_gsm.c26
-rw-r--r--drivers/tty/n_tty.c1
-rw-r--r--drivers/tty/serial/8250.c1
-rw-r--r--drivers/tty/serial/8250_pci.c61
-rw-r--r--drivers/tty/serial/amba-pl011.c123
-rw-r--r--drivers/tty/serial/atmel_serial.c3
-rw-r--r--drivers/tty/serial/bcm63xx_uart.c18
-rw-r--r--drivers/tty/serial/jsm/jsm_driver.c2
-rw-r--r--drivers/tty/serial/mrst_max3110.c5
-rw-r--r--drivers/tty/serial/pch_uart.c4
-rw-r--r--drivers/tty/serial/s5pv210.c4
-rw-r--r--drivers/tty/tty_ldisc.c4
12 files changed, 232 insertions, 20 deletions
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 09e8c7d53af3..19b4ae052af8 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -875,7 +875,8 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
 		*dp++ = last << 7 | first << 6 | 1;	/* EA */
 		len--;
 	}
-	memcpy(dp, skb_pull(dlci->skb, len), len);
+	memcpy(dp, dlci->skb->data, len);
+	skb_pull(dlci->skb, len);
 	__gsm_data_queue(dlci, msg);
 	if (last)
 		dlci->skb = NULL;
@@ -984,10 +985,22 @@ static void gsm_control_reply(struct gsm_mux *gsm, int cmd, u8 *data,
  */
 
 static void gsm_process_modem(struct tty_struct *tty, struct gsm_dlci *dlci,
-							u32 modem)
+							u32 modem, int clen)
 {
 	int  mlines = 0;
-	u8 brk = modem >> 6;
+	u8 brk = 0;
+
+	/* The modem status command can either contain one octet (v.24 signals)
+	   or two octets (v.24 signals + break signals). The length field will
+	   either be 2 or 3 respectively. This is specified in section
+	   5.4.6.3.7 of the  27.010 mux spec. */
+
+	if (clen == 2)
+		modem = modem & 0x7f;
+	else {
+		brk = modem & 0x7f;
+		modem = (modem >> 7) & 0x7f;
+	};
 
 	/* Flow control/ready to communicate */
 	if (modem & MDM_FC) {
@@ -1061,7 +1074,7 @@ static void gsm_control_modem(struct gsm_mux *gsm, u8 *data, int clen)
 			return;
 	}
 	tty = tty_port_tty_get(&dlci->port);
-	gsm_process_modem(tty, dlci, modem);
+	gsm_process_modem(tty, dlci, modem, clen);
 	if (tty) {
 		tty_wakeup(tty);
 		tty_kref_put(tty);
@@ -1482,12 +1495,13 @@ static void gsm_dlci_begin_close(struct gsm_dlci *dlci)
  *	open we shovel the bits down it, if not we drop them.
  */
 
-static void gsm_dlci_data(struct gsm_dlci *dlci, u8 *data, int len)
+static void gsm_dlci_data(struct gsm_dlci *dlci, u8 *data, int clen)
 {
 	/* krefs .. */
 	struct tty_port *port = &dlci->port;
 	struct tty_struct *tty = tty_port_tty_get(port);
 	unsigned int modem = 0;
+	int len = clen;
 
 	if (debug & 16)
 		pr_debug("%d bytes for tty %p\n", len, tty);
@@ -1507,7 +1521,7 @@ static void gsm_dlci_data(struct gsm_dlci *dlci, u8 *data, int len)
 				if (len == 0)
 					return;
 			}
-			gsm_process_modem(tty, dlci, modem);
+			gsm_process_modem(tty, dlci, modem, clen);
 		/* Line state will go via DLCI 0 controls only */
 		case 1:
 		default:
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 0ad32888091c..c3954fbf6ac4 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1815,6 +1815,7 @@ do_it_again:
 			/* FIXME: does n_tty_set_room need locking ? */
 			n_tty_set_room(tty);
 			timeout = schedule_timeout(timeout);
+			BUG_ON(!tty->read_buf);
 			continue;
 		}
 		__set_current_state(TASK_RUNNING);
diff --git a/drivers/tty/serial/8250.c b/drivers/tty/serial/8250.c
index b40f7b90c81d..b4129f53fb1b 100644
--- a/drivers/tty/serial/8250.c
+++ b/drivers/tty/serial/8250.c
@@ -3318,6 +3318,7 @@ void serial8250_unregister_port(int line)
 		uart->port.flags &= ~UPF_BOOT_AUTOCONF;
 		uart->port.type = PORT_UNKNOWN;
 		uart->port.dev = &serial8250_isa_devs->dev;
+		uart->capabilities = uart_config[uart->port.type].flags;
 		uart_add_one_port(&serial8250_reg, &uart->port);
 	} else {
 		uart->port.dev = NULL;
diff --git a/drivers/tty/serial/8250_pci.c b/drivers/tty/serial/8250_pci.c
index afb974b48b33..cf35e0dc5085 100644
--- a/drivers/tty/serial/8250_pci.c
+++ b/drivers/tty/serial/8250_pci.c
@@ -973,7 +973,7 @@ ce4100_serial_setup(struct serial_private *priv,
 
 static int
 pci_omegapci_setup(struct serial_private *priv,
-		      struct pciserial_board *board,
+		      const struct pciserial_board *board,
 		      struct uart_port *port, int idx)
 {
 	return setup_port(priv, port, 2, idx * 8, 0);
@@ -994,6 +994,15 @@ static int skip_tx_en_setup(struct serial_private *priv,
 	return pci_default_setup(priv, board, port, idx);
 }
 
+static int pci_eg20t_init(struct pci_dev *dev)
+{
+#if defined(CONFIG_SERIAL_PCH_UART) || defined(CONFIG_SERIAL_PCH_UART_MODULE)
+	return -ENODEV;
+#else
+	return 0;
+#endif
+}
+
 /* This should be in linux/pci_ids.h */
 #define PCI_VENDOR_ID_SBSMODULARIO	0x124B
 #define PCI_SUBVENDOR_ID_SBSMODULARIO	0x124B
@@ -1446,6 +1455,56 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = {
 		.init			= pci_oxsemi_tornado_init,
 		.setup		= pci_default_setup,
 	},
+	{
+		.vendor         = PCI_VENDOR_ID_INTEL,
+		.device         = 0x8811,
+		.init		= pci_eg20t_init,
+	},
+	{
+		.vendor         = PCI_VENDOR_ID_INTEL,
+		.device         = 0x8812,
+		.init		= pci_eg20t_init,
+	},
+	{
+		.vendor         = PCI_VENDOR_ID_INTEL,
+		.device         = 0x8813,
+		.init		= pci_eg20t_init,
+	},
+	{
+		.vendor         = PCI_VENDOR_ID_INTEL,
+		.device         = 0x8814,
+		.init		= pci_eg20t_init,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x8027,
+		.init		= pci_eg20t_init,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x8028,
+		.init		= pci_eg20t_init,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x8029,
+		.init		= pci_eg20t_init,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x800C,
+		.init		= pci_eg20t_init,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x800D,
+		.init		= pci_eg20t_init,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x800D,
+		.init		= pci_eg20t_init,
+	},
 	/*
 	 * Cronyx Omega PCI (PLX-chip based)
 	 */
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 8dc0541feecc..f5f6831b0a64 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -50,6 +50,7 @@
 #include <linux/dmaengine.h>
 #include <linux/dma-mapping.h>
 #include <linux/scatterlist.h>
+#include <linux/delay.h>
 
 #include <asm/io.h>
 #include <asm/sizes.h>
@@ -65,6 +66,30 @@
 #define UART_DR_ERROR		(UART011_DR_OE|UART011_DR_BE|UART011_DR_PE|UART011_DR_FE)
 #define UART_DUMMY_DR_RX	(1 << 16)
 
+
+#define UART_WA_SAVE_NR 14
+
+static void pl011_lockup_wa(unsigned long data);
+static const u32 uart_wa_reg[UART_WA_SAVE_NR] = {
+	ST_UART011_DMAWM,
+	ST_UART011_TIMEOUT,
+	ST_UART011_LCRH_RX,
+	UART011_IBRD,
+	UART011_FBRD,
+	ST_UART011_LCRH_TX,
+	UART011_IFLS,
+	ST_UART011_XFCR,
+	ST_UART011_XON1,
+	ST_UART011_XON2,
+	ST_UART011_XOFF1,
+	ST_UART011_XOFF2,
+	UART011_CR,
+	UART011_IMSC
+};
+
+static u32 uart_wa_regdata[UART_WA_SAVE_NR];
+static DECLARE_TASKLET(pl011_lockup_tlet, pl011_lockup_wa, 0);
+
 /* There is by now at least one vendor with differing details, so handle it */
 struct vendor_data {
 	unsigned int		ifls;
@@ -72,6 +97,7 @@ struct vendor_data {
 	unsigned int		lcrh_tx;
 	unsigned int		lcrh_rx;
 	bool			oversampling;
+	bool			interrupt_may_hang;   /* vendor-specific */
 	bool			dma_threshold;
 };
 
@@ -90,9 +116,12 @@ static struct vendor_data vendor_st = {
 	.lcrh_tx		= ST_UART011_LCRH_TX,
 	.lcrh_rx		= ST_UART011_LCRH_RX,
 	.oversampling		= true,
+	.interrupt_may_hang	= true,
 	.dma_threshold		= true,
 };
 
+static struct uart_amba_port *amba_ports[UART_NR];
+
 /* Deals with DMA transactions */
 
 struct pl011_sgbuf {
@@ -132,6 +161,7 @@ struct uart_amba_port {
 	unsigned int		lcrh_rx;	/* vendor-specific */
 	bool			autorts;
 	char			type[12];
+	bool			interrupt_may_hang; /* vendor-specific */
 #ifdef CONFIG_DMA_ENGINE
 	/* DMA stuff */
 	bool			using_tx_dma;
@@ -1008,6 +1038,68 @@ static inline bool pl011_dma_rx_running(struct uart_amba_port *uap)
 #endif
 
 
+/*
+ * pl011_lockup_wa
+ * This workaround aims to break the deadlock situation
+ * when after long transfer over uart in hardware flow
+ * control, uart interrupt registers cannot be cleared.
+ * Hence uart transfer gets blocked.
+ *
+ * It is seen that during such deadlock condition ICR
+ * don't get cleared even on multiple write. This leads
+ * pass_counter to decrease and finally reach zero. This
+ * can be taken as trigger point to run this UART_BT_WA.
+ *
+ */
+static void pl011_lockup_wa(unsigned long data)
+{
+	struct uart_amba_port *uap = amba_ports[0];
+	void __iomem *base = uap->port.membase;
+	struct circ_buf *xmit = &uap->port.state->xmit;
+	struct tty_struct *tty = uap->port.state->port.tty;
+	int buf_empty_retries = 200;
+	int loop;
+
+	/* Stop HCI layer from submitting data for tx */
+	tty->hw_stopped = 1;
+	while (!uart_circ_empty(xmit)) {
+		if (buf_empty_retries-- == 0)
+			break;
+		udelay(100);
+	}
+
+	/* Backup registers */
+	for (loop = 0; loop < UART_WA_SAVE_NR; loop++)
+		uart_wa_regdata[loop] = readl(base + uart_wa_reg[loop]);
+
+	/* Disable UART so that FIFO data is flushed out */
+	writew(0x00, uap->port.membase + UART011_CR);
+
+	/* Soft reset UART module */
+	if (uap->port.dev->platform_data) {
+		struct amba_pl011_data *plat;
+
+		plat = uap->port.dev->platform_data;
+		if (plat->reset)
+			plat->reset();
+	}
+
+	/* Restore registers */
+	for (loop = 0; loop < UART_WA_SAVE_NR; loop++)
+		writew(uart_wa_regdata[loop] ,
+				uap->port.membase + uart_wa_reg[loop]);
+
+	/* Initialise the old status of the modem signals */
+	uap->old_status = readw(uap->port.membase + UART01x_FR) &
+		UART01x_FR_MODEM_ANY;
+
+	if (readl(base + UART011_MIS) & 0x2)
+		printk(KERN_EMERG "UART_BT_WA: ***FAILED***\n");
+
+	/* Start Tx/Rx */
+	tty->hw_stopped = 0;
+}
+
 static void pl011_stop_tx(struct uart_port *port)
 {
 	struct uart_amba_port *uap = (struct uart_amba_port *)port;
@@ -1158,8 +1250,11 @@ static irqreturn_t pl011_int(int irq, void *dev_id)
 			if (status & UART011_TXIS)
 				pl011_tx_chars(uap);
 
-			if (pass_counter-- == 0)
+			if (pass_counter-- == 0) {
+				if (uap->interrupt_may_hang)
+					tasklet_schedule(&pl011_lockup_tlet);
 				break;
+			}
 
 			status = readw(uap->port.membase + UART011_MIS);
 		} while (status != 0);
@@ -1339,6 +1434,14 @@ static int pl011_startup(struct uart_port *port)
 	writew(uap->im, uap->port.membase + UART011_IMSC);
 	spin_unlock_irq(&uap->port.lock);
 
+	if (uap->port.dev->platform_data) {
+		struct amba_pl011_data *plat;
+
+		plat = uap->port.dev->platform_data;
+		if (plat->init)
+			plat->init();
+	}
+
 	return 0;
 
  clk_dis:
@@ -1394,6 +1497,15 @@ static void pl011_shutdown(struct uart_port *port)
 	 * Shut down the clock producer
 	 */
 	clk_disable(uap->clk);
+
+	if (uap->port.dev->platform_data) {
+		struct amba_pl011_data *plat;
+
+		plat = uap->port.dev->platform_data;
+		if (plat->exit)
+			plat->exit();
+	}
+
 }
 
 static void
@@ -1700,6 +1812,14 @@ static int __init pl011_console_setup(struct console *co, char *options)
 	if (!uap)
 		return -ENODEV;
 
+	if (uap->port.dev->platform_data) {
+		struct amba_pl011_data *plat;
+
+		plat = uap->port.dev->platform_data;
+		if (plat->init)
+			plat->init();
+	}
+
 	uap->port.uartclk = clk_get_rate(uap->clk);
 
 	if (options)
@@ -1774,6 +1894,7 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
 	uap->lcrh_rx = vendor->lcrh_rx;
 	uap->lcrh_tx = vendor->lcrh_tx;
 	uap->fifosize = vendor->fifosize;
+	uap->interrupt_may_hang = vendor->interrupt_may_hang;
 	uap->port.dev = &dev->dev;
 	uap->port.mapbase = dev->res.start;
 	uap->port.membase = base;
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 6d5d6e679fc7..af9b7814965a 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -1709,12 +1709,13 @@ static int atmel_serial_resume(struct platform_device *pdev)
 static int __devinit atmel_serial_probe(struct platform_device *pdev)
 {
 	struct atmel_uart_port *port;
+	struct atmel_uart_data *pdata = pdev->dev.platform_data;
 	void *data;
 	int ret;
 
 	BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
 
-	port = &atmel_ports[pdev->id];
+	port = &atmel_ports[pdata->num];
 	port->backup_imr = 0;
 
 	atmel_init_port(port, pdev);
diff --git a/drivers/tty/serial/bcm63xx_uart.c b/drivers/tty/serial/bcm63xx_uart.c
index a1a0e55d0807..c0b68b9cad91 100644
--- a/drivers/tty/serial/bcm63xx_uart.c
+++ b/drivers/tty/serial/bcm63xx_uart.c
@@ -250,6 +250,20 @@ static void bcm_uart_do_rx(struct uart_port *port)
 		/* get overrun/fifo empty information from ier
 		 * register */
 		iestat = bcm_uart_readl(port, UART_IR_REG);
+
+		if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) {
+			unsigned int val;
+
+			/* fifo reset is required to clear
+			 * interrupt */
+			val = bcm_uart_readl(port, UART_CTL_REG);
+			val |= UART_CTL_RSTRXFIFO_MASK;
+			bcm_uart_writel(port, val, UART_CTL_REG);
+
+			port->icount.overrun++;
+			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+		}
+
 		if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
 			break;
 
@@ -284,10 +298,6 @@ static void bcm_uart_do_rx(struct uart_port *port)
 		if (uart_handle_sysrq_char(port, c))
 			continue;
 
-		if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) {
-			port->icount.overrun++;
-			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
-		}
 
 		if ((cstat & port->ignore_status_mask) == 0)
 			tty_insert_flip_char(tty, c, flag);
diff --git a/drivers/tty/serial/jsm/jsm_driver.c b/drivers/tty/serial/jsm/jsm_driver.c
index 18f548449c63..96da17868cf3 100644
--- a/drivers/tty/serial/jsm/jsm_driver.c
+++ b/drivers/tty/serial/jsm/jsm_driver.c
@@ -125,7 +125,7 @@ static int __devinit jsm_probe_one(struct pci_dev *pdev, const struct pci_device
 	brd->bd_uart_offset = 0x200;
 	brd->bd_dividend = 921600;
 
-	brd->re_map_membase = ioremap(brd->membase, 0x1000);
+	brd->re_map_membase = ioremap(brd->membase, pci_resource_len(pdev, 0));
 	if (!brd->re_map_membase) {
 		dev_err(&pdev->dev,
 			"card has no PCI Memory resources, "
diff --git a/drivers/tty/serial/mrst_max3110.c b/drivers/tty/serial/mrst_max3110.c
index 1bd28450ca40..a764bf99743b 100644
--- a/drivers/tty/serial/mrst_max3110.c
+++ b/drivers/tty/serial/mrst_max3110.c
@@ -421,7 +421,6 @@ static int max3110_main_thread(void *_max)
 	int ret = 0;
 	struct circ_buf *xmit = &max->con_xmit;
 
-	init_waitqueue_head(wq);
 	pr_info(PR_FMT "start main thread\n");
 
 	do {
@@ -823,7 +822,7 @@ static int __devinit serial_m3110_probe(struct spi_device *spi)
 	res = RC_TAG;
 	ret = max3110_write_then_read(max, (u8 *)&res, (u8 *)&res, 2, 0);
 	if (ret < 0 || res == 0 || res == 0xffff) {
-		printk(KERN_ERR "MAX3111 deemed not present (conf reg %04x)",
+		dev_dbg(&spi->dev, "MAX3111 deemed not present (conf reg %04x)",
 									res);
 		ret = -ENODEV;
 		goto err_get_page;
@@ -838,6 +837,8 @@ static int __devinit serial_m3110_probe(struct spi_device *spi)
 	max->con_xmit.head = 0;
 	max->con_xmit.tail = 0;
 
+	init_waitqueue_head(&max->wq);
+
 	max->main_thread = kthread_run(max3110_main_thread,
 					max, "max3110_main");
 	if (IS_ERR(max->main_thread)) {
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index f2cb7503fcb2..465210930890 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -1397,6 +1397,7 @@ static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev,
 	int fifosize, base_baud;
 	int port_type;
 	struct pch_uart_driver_data *board;
+	const char *board_name;
 
 	board = &drv_dat[id->driver_data];
 	port_type = board->port_type;
@@ -1412,7 +1413,8 @@ static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev,
 	base_baud = 1843200; /* 1.8432MHz */
 
 	/* quirk for CM-iTC board */
-	if (strstr(dmi_get_system_info(DMI_BOARD_NAME), "CM-iTC"))
+	board_name = dmi_get_system_info(DMI_BOARD_NAME);
+	if (board_name && strstr(board_name, "CM-iTC"))
 		base_baud = 192000000; /* 192.0MHz */
 
 	switch (port_type) {
diff --git a/drivers/tty/serial/s5pv210.c b/drivers/tty/serial/s5pv210.c
index fb2619f93d84..dd194dc80ee9 100644
--- a/drivers/tty/serial/s5pv210.c
+++ b/drivers/tty/serial/s5pv210.c
@@ -30,7 +30,7 @@ static int s5pv210_serial_setsource(struct uart_port *port,
 	struct s3c2410_uartcfg *cfg = port->dev->platform_data;
 	unsigned long ucon = rd_regl(port, S3C2410_UCON);
 
-	if ((cfg->clocks_size) == 1)
+	if (cfg->flags & NO_NEED_CHECK_CLKSRC)
 		return 0;
 
 	if (strcmp(clk->name, "pclk") == 0)
@@ -55,7 +55,7 @@ static int s5pv210_serial_getsource(struct uart_port *port,
 
 	clk->divisor = 1;
 
-	if ((cfg->clocks_size) == 1)
+	if (cfg->flags & NO_NEED_CHECK_CLKSRC)
 		return 0;
 
 	switch (ucon & S5PV210_UCON_CLKMASK) {
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 5d01d32e2cf0..ef925d581713 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -555,7 +555,7 @@ static void tty_ldisc_flush_works(struct tty_struct *tty)
 static int tty_ldisc_wait_idle(struct tty_struct *tty)
 {
 	int ret;
-	ret = wait_event_interruptible_timeout(tty_ldisc_idle,
+	ret = wait_event_timeout(tty_ldisc_idle,
 			atomic_read(&tty->ldisc->users) == 1, 5 * HZ);
 	if (ret < 0)
 		return ret;
@@ -763,6 +763,8 @@ static int tty_ldisc_reinit(struct tty_struct *tty, int ldisc)
 	if (IS_ERR(ld))
 		return -1;
 
+	WARN_ON_ONCE(tty_ldisc_wait_idle(tty));
+
 	tty_ldisc_close(tty, tty->ldisc);
 	tty_ldisc_put(tty->ldisc);
 	tty->ldisc = NULL;