Merge tag 'tty-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here's the big tty/serial driver pull request for 3.14-rc1

  There are a number of n_tty fixes and cleanups, and some serial driver
  bugfixes, and we got rid of one obsolete driver, making this series
  remove more lines than added, always a nice surprise.

  All of these have been in linux-next with no reports of issues"

* tag 'tty-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (60 commits)
  tty/serial: at91: disable uart timer at start of shutdown
  serial: 8250: enable UART_BUG_NOMSR for Tegra
  tty/serial: at91: reset rx_ring when port is shutdown
  tty/serial: at91: fix race condition in atmel_serial_remove
  tty/serial: at91: Handle shutdown more safely
  serial: sirf: correct condition for fetching dma buffer into tty
  serial: sirf: provide pm entries of uart_ops
  serial: sirf: use PM macro initialize PM functions
  serial: clps711x: Enable driver compilation with COMPILE_TEST
  serial: clps711x: Add support for N_IRDA line discipline
  tty: synclink: avoid sleep_on race
  tty/amiserial: avoid interruptible_sleep_on
  tty: delete non-required instances of include <linux/init.h>
  tty: an overflow of multiplication in drivers/tty/cyclades.c
  serial: Remove old SC26XX driver
  serial: add support for 200 v3 series Titan card
  serial: 8250: Fix initialisation of Quatech cards with the AMCC PCI chip
  tty: Removing the deprecated function tty_vhangup_locked()
  TTY/n_gsm: Removing the wrong tty_unlock/lock() in gsm_dlci_release()
  tty/serial: at91: document clock properties
  ...

Documentation/devicetree/bindings/serial/atmel-usart.txt

@@ -6,6 +6,9 @@ Required properties:
   additional mode or an USART new feature.
 - reg: Should contain registers location and length
 - interrupts: Should contain interrupt
+- clock-names: tuple listing input clock names.
+	Required elements: "usart"
+- clocks: phandles to input clocks.
 
 Optional properties:
 - atmel,use-dma-rx: use of PDC or DMA for receiving data
@@ -26,6 +29,8 @@ Example:
 		compatible = "atmel,at91sam9260-usart";
 		reg = <0xfff8c000 0x4000>;
 		interrupts = <7>;
+		clocks = <&usart0_clk>;
+		clock-names = "usart";
 		atmel,use-dma-rx;
 		atmel,use-dma-tx;
 	};
@@ -35,6 +40,8 @@ Example:
 		compatible = "atmel,at91sam9260-usart";
 		reg = <0xf001c000 0x100>;
 		interrupts = <12 4 5>;
+		clocks = <&usart0_clk>;
+		clock-names = "usart";
 		atmel,use-dma-rx;
 		atmel,use-dma-tx;
 		dmas = <&dma0 2 0x3>,

Documentation/devicetree/bindings/serial/cirrus,clps711x-uart.txt

@@ -0,0 +1,28 @@
+* Cirrus Logic CLPS711X Universal Asynchronous Receiver/Transmitter (UART)
+
+Required properties:
+- compatible: Should be "cirrus,clps711x-uart".
+- reg: Address and length of the register set for the device.
+- interrupts: Should contain UART TX and RX interrupt.
+- clocks: Should contain UART core clock number.
+- syscon: Phandle to SYSCON node, which contain UART control bits.
+
+Optional properties:
+- uart-use-ms: Indicate the UART has modem signal (DCD, DSR, CTS).
+
+Note: Each UART port should have an alias correctly numbered
+in "aliases" node.
+
+Example:
+	aliases {
+		serial0 = &uart1;
+	};
+
+	uart1: uart@80000480 {
+		compatible = "cirrus,clps711x-uart";
+		reg = <0x80000480 0x80>;
+		interrupts = <12 13>;
+		clocks = <&clks 11>;
+		syscon = <&syscon1>;
+		uart-use-ms;
+	};

arch/arm/mach-clps711x/devices.c

@@ -61,8 +61,29 @@ static void __init clps711x_add_syscon(void)
 						&clps711x_syscon_res[i], 1);
 }
 
+static const struct resource clps711x_uart1_res[] __initconst = {
+	DEFINE_RES_MEM(CLPS711X_PHYS_BASE + UARTDR1, SZ_128),
+	DEFINE_RES_IRQ(IRQ_UTXINT1),
+	DEFINE_RES_IRQ(IRQ_URXINT1),
+};
+
+static const struct resource clps711x_uart2_res[] __initconst = {
+	DEFINE_RES_MEM(CLPS711X_PHYS_BASE + UARTDR2, SZ_128),
+	DEFINE_RES_IRQ(IRQ_UTXINT2),
+	DEFINE_RES_IRQ(IRQ_URXINT2),
+};
+
+static void __init clps711x_add_uart(void)
+{
+	platform_device_register_simple("clps711x-uart", 0, clps711x_uart1_res,
+					ARRAY_SIZE(clps711x_uart1_res));
+	platform_device_register_simple("clps711x-uart", 1, clps711x_uart2_res,
+					ARRAY_SIZE(clps711x_uart2_res));
+};
+
 void __init clps711x_devices_init(void)
 {
 	clps711x_add_gpio();
 	clps711x_add_syscon();
+	clps711x_add_uart();
 }

drivers/char/pcmcia/synclink_cs.c

@@ -2511,8 +2511,8 @@ static int mgslpc_open(struct tty_struct *tty, struct file * filp)
 
 	/* If port is closing, signal caller to try again */
 	if (tty_hung_up_p(filp) || port->flags & ASYNC_CLOSING){
-		if (port->flags & ASYNC_CLOSING)
-			interruptible_sleep_on(&port->close_wait);
+		wait_event_interruptible_tty(tty, port->close_wait,
+					     !(port->flags & ASYNC_CLOSING));
 		retval = ((port->flags & ASYNC_HUP_NOTIFY) ?
 			-EAGAIN : -ERESTARTSYS);
 		goto cleanup;

drivers/input/serio/serport.c

@@ -124,7 +124,7 @@ static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *c
 {
 	struct serport *serport = (struct serport*) tty->disc_data;
 	unsigned long flags;
-	unsigned int ch_flags;
+	unsigned int ch_flags = 0;
 	int i;
 
 	spin_lock_irqsave(&serport->lock, flags);
@@ -133,18 +133,20 @@ static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *c
 		goto out;
 
 	for (i = 0; i < count; i++) {
-		switch (fp[i]) {
-		case TTY_FRAME:
-			ch_flags = SERIO_FRAME;
-			break;
+		if (fp) {
+			switch (fp[i]) {
+			case TTY_FRAME:
+				ch_flags = SERIO_FRAME;
+				break;
 
-		case TTY_PARITY:
-			ch_flags = SERIO_PARITY;
-			break;
+			case TTY_PARITY:
+				ch_flags = SERIO_PARITY;
+				break;
 
-		default:
-			ch_flags = 0;
-			break;
+			default:
+				ch_flags = 0;
+				break;
+			}
 		}
 
 		serio_interrupt(serport->serio, cp[i], ch_flags);

drivers/parport/parport_serial.c

@@ -596,13 +596,11 @@ static int parport_serial_pci_probe(struct pci_dev *dev,
 
 	err = pci_enable_device (dev);
 	if (err) {
-		pci_set_drvdata (dev, NULL);
 		kfree (priv);
 		return err;
 	}
 
 	if (parport_register (dev, id)) {
-		pci_set_drvdata (dev, NULL);
 		kfree (priv);
 		return -ENODEV;
 	}
@@ -611,7 +609,6 @@ static int parport_serial_pci_probe(struct pci_dev *dev,
 		int i;
 		for (i = 0; i < priv->num_par; i++)
 			parport_pc_unregister_port (priv->port[i]);
-		pci_set_drvdata (dev, NULL);
 		kfree (priv);
 		return -ENODEV;
 	}
@@ -624,8 +621,6 @@ static void parport_serial_pci_remove(struct pci_dev *dev)
 	struct parport_serial_private *priv = pci_get_drvdata (dev);
 	int i;
 
-	pci_set_drvdata(dev, NULL);
-
 	// Serial ports
 	if (priv->serial)
 		pciserial_remove_ports(priv->serial);

drivers/staging/fwserial/Kconfig

@@ -9,3 +9,23 @@ config FIREWIRE_SERIAL
 
 	  To compile this driver as a module, say M here:  the module will
 	  be called firewire-serial.
+
+if FIREWIRE_SERIAL
+
+config FWTTY_MAX_TOTAL_PORTS
+       int "Maximum number of serial ports supported"
+       default "64"
+       help
+          Set this to the maximum number of serial ports you want the
+	  firewire-serial driver to support.
+
+config FWTTY_MAX_CARD_PORTS
+       int "Maximum number of serial ports supported per adapter"
+       range 0 FWTTY_MAX_TOTAL_PORTS
+       default "32"
+       help
+          Set this to the maximum number of serial ports each firewire
+	  adapter supports. The actual number of serial ports registered
+	  is set with the module parameter "ttys".
+
+endif

drivers/staging/fwserial/fwserial.c

@@ -136,14 +136,14 @@ static struct fwtty_peer *__fwserial_peer_by_node_id(struct fw_card *card,
 
 #ifdef FWTTY_PROFILING
 
-static void profile_fifo_avail(struct fwtty_port *port, unsigned *stat)
+static void fwtty_profile_fifo(struct fwtty_port *port, unsigned *stat)
 {
 	spin_lock_bh(&port->lock);
-	profile_size_distrib(stat, dma_fifo_avail(&port->tx_fifo));
+	fwtty_profile_data(stat, dma_fifo_avail(&port->tx_fifo));
 	spin_unlock_bh(&port->lock);
 }
 
-static void dump_profile(struct seq_file *m, struct stats *stats)
+static void fwtty_dump_profile(struct seq_file *m, struct stats *stats)
 {
 	/* for each stat, print sum of 0 to 2^k, then individually */
 	int k = 4;
@@ -183,8 +183,8 @@ static void dump_profile(struct seq_file *m, struct stats *stats)
 }
 
 #else
-#define profile_fifo_avail(port, stat)
-#define dump_profile(m, stats)
+#define fwtty_profile_fifo(port, stat)
+#define fwtty_dump_profile(m, stats)
 #endif
 
 /*
@@ -456,16 +456,27 @@ static int fwtty_write_port_status(struct fwtty_port *port)
 	return err;
 }
 
-static void __fwtty_throttle(struct fwtty_port *port, struct tty_struct *tty)
+static void fwtty_throttle_port(struct fwtty_port *port)
 {
+	struct tty_struct *tty;
 	unsigned old;
 
+	tty = tty_port_tty_get(&port->port);
+	if (!tty)
+		return;
+
+	spin_lock_bh(&port->lock);
+
 	old = port->mctrl;
 	port->mctrl |= OOB_RX_THROTTLE;
 	if (C_CRTSCTS(tty))
 		port->mctrl &= ~TIOCM_RTS;
 	if (~old & OOB_RX_THROTTLE)
 		__fwtty_write_port_status(port);
+
+	spin_unlock_bh(&port->lock);
+
+	tty_kref_put(tty);
 }
 
 /**
@@ -532,80 +543,14 @@ static void fwtty_emit_breaks(struct work_struct *work)
 	port->icount.brk += brk;
 }
 
-static void fwtty_pushrx(struct work_struct *work)
-{
-	struct fwtty_port *port = to_port(work, push);
-	struct tty_struct *tty;
-	struct buffered_rx *buf, *next;
-	int n, c = 0;
-
-	spin_lock_bh(&port->lock);
-	list_for_each_entry_safe(buf, next, &port->buf_list, list) {
-		n = tty_insert_flip_string_fixed_flag(&port->port, buf->data,
-						      TTY_NORMAL, buf->n);
-		c += n;
-		port->buffered -= n;
-		if (n < buf->n) {
-			if (n > 0) {
-				memmove(buf->data, buf->data + n, buf->n - n);
-				buf->n -= n;
-			}
-			tty = tty_port_tty_get(&port->port);
-			if (tty) {
-				__fwtty_throttle(port, tty);
-				tty_kref_put(tty);
-			}
-			break;
-		} else {
-			list_del(&buf->list);
-			kfree(buf);
-		}
-	}
-	if (c > 0)
-		tty_flip_buffer_push(&port->port);
-
-	if (list_empty(&port->buf_list))
-		clear_bit(BUFFERING_RX, &port->flags);
-	spin_unlock_bh(&port->lock);
-}
-
-static int fwtty_buffer_rx(struct fwtty_port *port, unsigned char *d, size_t n)
-{
-	struct buffered_rx *buf;
-	size_t size = (n + sizeof(struct buffered_rx) + 0xFF) & ~0xFF;
-
-	if (port->buffered + n > HIGH_WATERMARK) {
-		fwtty_err_ratelimited(port, "overflowed rx buffer: buffered: %d new: %zu wtrmk: %d\n",
-				      port->buffered, n, HIGH_WATERMARK);
-		return 0;
-	}
-	buf = kmalloc(size, GFP_ATOMIC);
-	if (!buf)
-		return 0;
-	INIT_LIST_HEAD(&buf->list);
-	buf->n = n;
-	memcpy(buf->data, d, n);
-
-	spin_lock_bh(&port->lock);
-	list_add_tail(&buf->list, &port->buf_list);
-	port->buffered += n;
-	if (port->buffered > port->stats.watermark)
-		port->stats.watermark = port->buffered;
-	set_bit(BUFFERING_RX, &port->flags);
-	spin_unlock_bh(&port->lock);
-
-	return n;
-}
-
 static int fwtty_rx(struct fwtty_port *port, unsigned char *data, size_t len)
 {
-	struct tty_struct *tty;
 	int c, n = len;
 	unsigned lsr;
 	int err = 0;
 
 	fwtty_dbg(port, "%d\n", n);
-	profile_size_distrib(port->stats.reads, n);
+	fwtty_profile_data(port->stats.reads, n);
 
 	if (port->write_only) {
 		n = 0;
@@ -636,31 +581,24 @@ static int fwtty_rx(struct fwtty_port *port, unsigned char *data, size_t len)
 		goto out;
 	}
 
-	if (!test_bit(BUFFERING_RX, &port->flags)) {
-		c = tty_insert_flip_string_fixed_flag(&port->port, data,
-				TTY_NORMAL, n);
-		if (c > 0)
-			tty_flip_buffer_push(&port->port);
-		n -= c;
-
-		if (n) {
-			/* start buffering and throttling */
-			n -= fwtty_buffer_rx(port, &data[c], n);
-
-			tty = tty_port_tty_get(&port->port);
-			if (tty) {
-				spin_lock_bh(&port->lock);
-				__fwtty_throttle(port, tty);
-				spin_unlock_bh(&port->lock);
-				tty_kref_put(tty);
-			}
-		}
-	} else
-		n -= fwtty_buffer_rx(port, data, n);
+	c = tty_insert_flip_string_fixed_flag(&port->port, data, TTY_NORMAL, n);
+	if (c > 0)
+		tty_flip_buffer_push(&port->port);
+	n -= c;
 
 	if (n) {
 		port->overrun = true;
 		err = -EIO;
+		fwtty_err_ratelimited(port, "flip buffer overrun\n");
+
+	} else {
+		/* throttle the sender if remaining flip buffer space has
+		 * reached high watermark to avoid losing data which may be
+		 * in-flight. Since the AR request context is 32k, that much
+		 * data may have _already_ been acked.
+		 */
+		if (tty_buffer_space_avail(&port->port) < HIGH_WATERMARK)
+			fwtty_throttle_port(port);
 	}
 
 out:
@@ -821,7 +759,7 @@ static int fwtty_tx(struct fwtty_port *port, bool drain)
 			if (n == -EAGAIN)
 				++port->stats.tx_stall;
 			else if (n == -ENODATA)
-				profile_size_distrib(port->stats.txns, 0);
+				fwtty_profile_data(port->stats.txns, 0);
 			else {
 				++port->stats.fifo_errs;
 				fwtty_err_ratelimited(port, "fifo err: %d\n",
@@ -830,7 +768,7 @@ static int fwtty_tx(struct fwtty_port *port, bool drain)
 			break;
 		}
 
-		profile_size_distrib(port->stats.txns, txn->dma_pended.len);
+		fwtty_profile_data(port->stats.txns, txn->dma_pended.len);
 
 		fwtty_send_txn_async(peer, txn, TCODE_WRITE_BLOCK_REQUEST,
 				     peer->fifo_addr, txn->dma_pended.data,
@@ -1101,20 +1039,13 @@ static int fwtty_port_activate(struct tty_port *tty_port,
 static void fwtty_port_shutdown(struct tty_port *tty_port)
 {
 	struct fwtty_port *port = to_port(tty_port, port);
-	struct buffered_rx *buf, *next;
 
 	/* TODO: cancel outstanding transactions */
 
 	cancel_delayed_work_sync(&port->emit_breaks);
 	cancel_delayed_work_sync(&port->drain);
-	cancel_work_sync(&port->push);
 
 	spin_lock_bh(&port->lock);
-	list_for_each_entry_safe(buf, next, &port->buf_list, list) {
-		list_del(&buf->list);
-		kfree(buf);
-	}
-	port->buffered = 0;
 	port->flags = 0;
 	port->break_ctl = 0;
 	port->overrun = 0;
@@ -1184,7 +1115,7 @@ static int fwtty_write(struct tty_struct *tty, const unsigned char *buf, int c)
 	int n, len;
 
 	fwtty_dbg(port, "%d\n", c);
-	profile_size_distrib(port->stats.writes, c);
+	fwtty_profile_data(port->stats.writes, c);
 
 	spin_lock_bh(&port->lock);
 	n = dma_fifo_in(&port->tx_fifo, buf, c);
@@ -1262,9 +1193,7 @@ static void fwtty_unthrottle(struct tty_struct *tty)
 
 	fwtty_dbg(port, "CRTSCTS: %d\n", (C_CRTSCTS(tty) != 0));
 
-	profile_fifo_avail(port, port->stats.unthrottle);
-
-	schedule_work(&port->push);
+	fwtty_profile_fifo(port, port->stats.unthrottle);
 
 	spin_lock_bh(&port->lock);
 	port->mctrl &= ~OOB_RX_THROTTLE;
@@ -1523,15 +1452,14 @@ static void fwtty_debugfs_show_port(struct seq_file *m, struct fwtty_port *port)
 
 	seq_printf(m, " dr:%d st:%d err:%d lost:%d", stats.dropped,
 		   stats.tx_stall, stats.fifo_errs, stats.lost);
-	seq_printf(m, " pkts:%d thr:%d wtrmk:%d", stats.sent, stats.throttled,
-		   stats.watermark);
+	seq_printf(m, " pkts:%d thr:%d", stats.sent, stats.throttled);
 
 	if (port->port.console) {
 		seq_puts(m, "\n    ");
 		(*port->fwcon_ops->proc_show)(m, port->con_data);
 	}
 
-	dump_profile(m, &port->stats);
+	fwtty_dump_profile(m, &port->stats);
 }
 
 static void fwtty_debugfs_show_peer(struct seq_file *m, struct fwtty_peer *peer)
@@ -2297,13 +2225,12 @@ static int fwserial_create(struct fw_unit *unit)
 		port->index = FWTTY_INVALID_INDEX;
 		port->port.ops = &fwtty_port_ops;
 		port->serial = serial;
+		tty_buffer_set_limit(&port->port, 128 * 1024);
 
 		spin_lock_init(&port->lock);
 		INIT_DELAYED_WORK(&port->drain, fwtty_drain_tx);
 		INIT_DELAYED_WORK(&port->emit_breaks, fwtty_emit_breaks);
 		INIT_WORK(&port->hangup, fwtty_do_hangup);
-		INIT_WORK(&port->push, fwtty_pushrx);
-		INIT_LIST_HEAD(&port->buf_list);
 		init_waitqueue_head(&port->wait_tx);
 		port->max_payload = link_speed_to_max_payload(SCODE_100);
 		dma_fifo_init(&port->tx_fifo);

drivers/staging/fwserial/fwserial.h

@@ -22,14 +22,14 @@
 #ifdef FWTTY_PROFILING
 #define DISTRIBUTION_MAX_SIZE     8192
 #define DISTRIBUTION_MAX_INDEX    (ilog2(DISTRIBUTION_MAX_SIZE) + 1)
-static inline void profile_size_distrib(unsigned stat[], unsigned val)
+static inline void fwtty_profile_data(unsigned stat[], unsigned val)
 {
 	int n = (val) ? min(ilog2(val) + 1, DISTRIBUTION_MAX_INDEX) : 0;
 	++stat[n];
 }
 #else
 #define DISTRIBUTION_MAX_INDEX    0
-#define profile_size_distrib(st, n)
+#define fwtty_profile_data(st, n)
 #endif
 
 /* Parameters for both VIRT_CABLE_PLUG & VIRT_CABLE_PLUG_RSP mgmt codes */
@@ -166,7 +166,6 @@ struct stats {
 	unsigned	sent;
 	unsigned	lost;
 	unsigned	throttled;
-	unsigned	watermark;
 	unsigned	reads[DISTRIBUTION_MAX_INDEX + 1];
 	unsigned	writes[DISTRIBUTION_MAX_INDEX + 1];
 	unsigned	txns[DISTRIBUTION_MAX_INDEX + 1];
@@ -183,12 +182,6 @@ struct fwconsole_ops {
 #define FWCON_NOTIFY_ATTACH		1
 #define FWCON_NOTIFY_DETACH		2
 
-struct buffered_rx {
-	struct list_head	list;
-	size_t			n;
-	unsigned char		data[0];
-};
-
 /**
  * fwtty_port: structure used to track/represent underlying tty_port
  * @port: underlying tty_port
@@ -223,11 +216,6 @@ struct buffered_rx {
  *         The work can race with the writer but concurrent sending is
  *         prevented with the IN_TX flag. Scheduled under lock to
  *         limit scheduling when fifo has just been drained.
- * @push: work responsible for pushing buffered rx to the ldisc.
- *	  rx can become buffered if the tty buffer is filled before the
- *	  ldisc throttles the sender.
- * @buf_list: list of buffered rx yet to be sent to ldisc
- * @buffered: byte count of buffered rx
  * @tx_fifo: fifo used to store & block-up writes for dma to remote
  * @max_payload: max bytes transmissable per dma (based on peer's max_payload)
  * @status_mask: UART_LSR_* bitmask significant to rx (based on termios)
@@ -267,9 +255,6 @@ struct fwtty_port {
 	spinlock_t		   lock;
 	unsigned		   mctrl;
 	struct delayed_work	   drain;
-	struct work_struct	   push;
-	struct list_head	   buf_list;
-	int			   buffered;
 	struct dma_fifo		   tx_fifo;
 	int			   max_payload;
 	unsigned		   status_mask;
@@ -291,7 +276,6 @@ struct fwtty_port {
 /* bit #s for flags field */
 #define IN_TX                      0
 #define STOP_TX                    1
-#define BUFFERING_RX		   2
 
 /* bitmasks for special mctrl/mstatus bits */
 #define OOB_RX_THROTTLE   0x00010000
@@ -307,8 +291,8 @@ struct fwtty_port {
 #define FREQ_BREAKS        (HZ / 50)
 
 /* Ports are allocated in blocks of num_ports for each fw_card */
-#define MAX_CARD_PORTS           32	/* max # of ports per card */
-#define MAX_TOTAL_PORTS          64	/* max # of ports total    */
+#define MAX_CARD_PORTS           CONFIG_FWTTY_MAX_CARD_PORTS
+#define MAX_TOTAL_PORTS          CONFIG_FWTTY_MAX_TOTAL_PORTS
 
 /* tuning parameters */
 #define FWTTY_PORT_TXFIFO_LEN	4096

drivers/tty/amiserial.c

@@ -1248,6 +1248,8 @@ static int rs_ioctl(struct tty_struct *tty,
 	struct async_icount cprev, cnow;	/* kernel counter temps */
 	void __user *argp = (void __user *)arg;
 	unsigned long flags;
+	DEFINE_WAIT(wait);
+	int ret;
 
 	if (serial_paranoia_check(info, tty->name, "rs_ioctl"))
 		return -ENODEV;
@@ -1288,25 +1290,33 @@ static int rs_ioctl(struct tty_struct *tty,
 			cprev = info->icount;
 			local_irq_restore(flags);
 			while (1) {
-				interruptible_sleep_on(&info->tport.delta_msr_wait);
-				/* see if a signal did it */
-				if (signal_pending(current))
-					return -ERESTARTSYS;
+				prepare_to_wait(&info->tport.delta_msr_wait,
+						&wait, TASK_INTERRUPTIBLE);
 				local_irq_save(flags);
 				cnow = info->icount; /* atomic copy */
 				local_irq_restore(flags);
 				if (cnow.rng == cprev.rng && cnow.dsr == cprev.dsr && 
-				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts)
-					return -EIO; /* no change => error */
+				    cnow.dcd == cprev.dcd && cnow.cts == cprev.cts) {
+					ret = -EIO; /* no change => error */
+					break;
+				}
 				if ( ((arg & TIOCM_RNG) && (cnow.rng != cprev.rng)) ||
 				     ((arg & TIOCM_DSR) && (cnow.dsr != cprev.dsr)) ||
 				     ((arg & TIOCM_CD)  && (cnow.dcd != cprev.dcd)) ||
 				     ((arg & TIOCM_CTS) && (cnow.cts != cprev.cts)) ) {
-					return 0;
+					ret = 0;
+					break;
+				}
+				schedule();
+				/* see if a signal did it */
+				if (signal_pending(current)) {
+					ret = -ERESTARTSYS;
+					break;
 				}
 				cprev = cnow;
 			}
-			/* NOTREACHED */
+			finish_wait(&info->tport.delta_msr_wait, &wait);
+			return ret;
 
 		case TIOCSERGWILD:
 		case TIOCSERSWILD:

drivers/tty/cyclades.c

@@ -2709,6 +2709,8 @@ cy_ioctl(struct tty_struct *tty,
 		break;
 #ifndef CONFIG_CYZ_INTR
 	case CYZSETPOLLCYCLE:
+		if (arg > LONG_MAX / HZ)
+			return -ENODEV;
 		cyz_polling_cycle = (arg * HZ) / 1000;
 		break;
 	case CYZGETPOLLCYCLE:

drivers/tty/goldfish.c

@@ -14,7 +14,6 @@
  */
 
 #include <linux/console.h>
-#include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/tty.h>

drivers/tty/hvc/hvc_console.c

@@ -788,7 +788,7 @@ static int hvc_tiocmset(struct tty_struct *tty,
 }
 
 #ifdef CONFIG_CONSOLE_POLL
-int hvc_poll_init(struct tty_driver *driver, int line, char *options)
+static int hvc_poll_init(struct tty_driver *driver, int line, char *options)
 {
 	return 0;
 }

drivers/tty/hvc/hvsi_lib.c

@@ -1,5 +1,4 @@
 #include <linux/types.h>
-#include <linux/init.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/console.h>

drivers/tty/ipwireless/tty.c

@@ -15,7 +15,6 @@
  *   Copyright (C) 2007 David Sterba
  */
 
-#include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/mutex.h>

drivers/tty/n_gsm.c

@@ -194,6 +194,7 @@ struct gsm_control {
 struct gsm_mux {
 	struct tty_struct *tty;		/* The tty our ldisc is bound to */
 	spinlock_t lock;
+	struct mutex mutex;
 	unsigned int num;
 	struct kref ref;
 
@@ -1704,11 +1705,8 @@ static void gsm_dlci_release(struct gsm_dlci *dlci)
 		gsm_destroy_network(dlci);
 		mutex_unlock(&dlci->mutex);
 
-		/* tty_vhangup needs the tty_lock, so unlock and
-		   relock after doing the hangup. */
-		tty_unlock(tty);
 		tty_vhangup(tty);
-		tty_lock(tty);
+
 		tty_port_tty_set(&dlci->port, NULL);
 		tty_kref_put(tty);
 	}
@@ -2019,7 +2017,7 @@ static void gsm_error(struct gsm_mux *gsm,
  *	and then shut down each device hanging up the channels as we go.
  */
 
-void gsm_cleanup_mux(struct gsm_mux *gsm)
+static void gsm_cleanup_mux(struct gsm_mux *gsm)
 {
 	int i;
 	struct gsm_dlci *dlci = gsm->dlci[0];
@@ -2054,15 +2052,16 @@ void gsm_cleanup_mux(struct gsm_mux *gsm)
 					dlci->state == DLCI_CLOSED);
 	}
 	/* Free up any link layer users */
+	mutex_lock(&gsm->mutex);
 	for (i = 0; i < NUM_DLCI; i++)
 		if (gsm->dlci[i])
 			gsm_dlci_release(gsm->dlci[i]);
+	mutex_unlock(&gsm->mutex);
 	/* Now wipe the queues */
 	list_for_each_entry_safe(txq, ntxq, &gsm->tx_list, list)
 		kfree(txq);
 	INIT_LIST_HEAD(&gsm->tx_list);
 }
-EXPORT_SYMBOL_GPL(gsm_cleanup_mux);
 
 /**
  *	gsm_activate_mux	-	generic GSM setup
@@ -2073,7 +2072,7 @@ EXPORT_SYMBOL_GPL(gsm_cleanup_mux);
  *	finally kick off connecting to DLCI 0 on the modem.
  */
 
-int gsm_activate_mux(struct gsm_mux *gsm)
+static int gsm_activate_mux(struct gsm_mux *gsm)
 {
 	struct gsm_dlci *dlci;
 	int i = 0;
@@ -2109,7 +2108,6 @@ int gsm_activate_mux(struct gsm_mux *gsm)
 	gsm->dead = 0;		/* Tty opens are now permissible */
 	return 0;
 }
-EXPORT_SYMBOL_GPL(gsm_activate_mux);
 
 /**
  *	gsm_free_mux		-	free up a mux
@@ -2117,13 +2115,12 @@ EXPORT_SYMBOL_GPL(gsm_activate_mux);
  *
  *	Dispose of allocated resources for a dead mux
  */
-void gsm_free_mux(struct gsm_mux *gsm)
+static void gsm_free_mux(struct gsm_mux *gsm)
 {
 	kfree(gsm->txframe);
 	kfree(gsm->buf);
 	kfree(gsm);
 }
-EXPORT_SYMBOL_GPL(gsm_free_mux);
 
 /**
  *	gsm_free_muxr		-	free up a mux
@@ -2153,7 +2150,7 @@ static inline void mux_put(struct gsm_mux *gsm)
  *	Creates a new mux ready for activation.
  */
 
-struct gsm_mux *gsm_alloc_mux(void)
+static struct gsm_mux *gsm_alloc_mux(void)
 {
 	struct gsm_mux *gsm = kzalloc(sizeof(struct gsm_mux), GFP_KERNEL);
 	if (gsm == NULL)
@@ -2170,6 +2167,7 @@ struct gsm_mux *gsm_alloc_mux(void)
 		return NULL;
 	}
 	spin_lock_init(&gsm->lock);
+	mutex_init(&gsm->mutex);
 	kref_init(&gsm->ref);
 	INIT_LIST_HEAD(&gsm->tx_list);
 
@@ -2185,7 +2183,6 @@ struct gsm_mux *gsm_alloc_mux(void)
 
 	return gsm;
 }
-EXPORT_SYMBOL_GPL(gsm_alloc_mux);
 
 /**
  *	gsmld_output		-	write to link
@@ -2269,14 +2266,15 @@ static void gsmld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 	char *f;
 	int i;
 	char buf[64];
-	char flags;
+	char flags = TTY_NORMAL;
 
 	if (debug & 4)
 		print_hex_dump_bytes("gsmld_receive: ", DUMP_PREFIX_OFFSET,
 				     cp, count);
 
 	for (i = count, dp = cp, f = fp; i; i--, dp++) {
-		flags = *f++;
+		if (f)
+			flags = *f++;
 		switch (flags) {
 		case TTY_NORMAL:
 			gsm->receive(gsm, *dp);
@@ -2711,7 +2709,7 @@ static void gsm_mux_rx_netchar(struct gsm_dlci *dlci,
 	return;
 }
 
-int gsm_change_mtu(struct net_device *net, int new_mtu)
+static int gsm_change_mtu(struct net_device *net, int new_mtu)
 {
 	struct gsm_mux_net *mux_net = (struct gsm_mux_net *)netdev_priv(net);
 	if ((new_mtu < 8) || (new_mtu > mux_net->dlci->gsm->mtu))
@@ -2909,23 +2907,33 @@ static int gsmtty_install(struct tty_driver *driver, struct tty_struct *tty)
 	This is ok from a locking
 	perspective as we don't have to worry about this
 	if DLCI0 is lost */
-	if (gsm->dlci[0] && gsm->dlci[0]->state != DLCI_OPEN)
+	mutex_lock(&gsm->mutex);
+	if (gsm->dlci[0] && gsm->dlci[0]->state != DLCI_OPEN) {
+		mutex_unlock(&gsm->mutex);
 		return -EL2NSYNC;
+	}
 	dlci = gsm->dlci[line];
 	if (dlci == NULL) {
 		alloc = true;
 		dlci = gsm_dlci_alloc(gsm, line);
 	}
-	if (dlci == NULL)
+	if (dlci == NULL) {
+		mutex_unlock(&gsm->mutex);
 		return -ENOMEM;
+	}
 	ret = tty_port_install(&dlci->port, driver, tty);
 	if (ret) {
 		if (alloc)
 			dlci_put(dlci);
+		mutex_unlock(&gsm->mutex);
 		return ret;
 	}
 
+	dlci_get(dlci);
+	dlci_get(gsm->dlci[0]);
+	mux_get(gsm);
 	tty->driver_data = dlci;
+	mutex_unlock(&gsm->mutex);
 
 	return 0;
 }
@@ -2936,9 +2944,6 @@ static int gsmtty_open(struct tty_struct *tty, struct file *filp)
 	struct tty_port *port = &dlci->port;
 
 	port->count++;
-	dlci_get(dlci);
-	dlci_get(dlci->gsm->dlci[0]);
-	mux_get(dlci->gsm);
 	tty_port_tty_set(port, tty);
 
 	dlci->modem_rx = 0;
@@ -2965,7 +2970,7 @@ static void gsmtty_close(struct tty_struct *tty, struct file *filp)
 	mutex_unlock(&dlci->mutex);
 	gsm = dlci->gsm;
 	if (tty_port_close_start(&dlci->port, tty, filp) == 0)
-		goto out;
+		return;
 	gsm_dlci_begin_close(dlci);
 	if (test_bit(ASYNCB_INITIALIZED, &dlci->port.flags)) {
 		if (C_HUPCL(tty))
@@ -2973,10 +2978,7 @@ static void gsmtty_close(struct tty_struct *tty, struct file *filp)
 	}
 	tty_port_close_end(&dlci->port, tty);
 	tty_port_tty_set(&dlci->port, NULL);
-out:
-	dlci_put(dlci);
-	dlci_put(gsm->dlci[0]);
-	mux_put(gsm);
+	return;
 }
 
 static void gsmtty_hangup(struct tty_struct *tty)
@@ -3153,6 +3155,16 @@ static int gsmtty_break_ctl(struct tty_struct *tty, int state)
 	return gsmtty_modem_update(dlci, encode);
 }
 
+static void gsmtty_remove(struct tty_driver *driver, struct tty_struct *tty)
+{
+	struct gsm_dlci *dlci = tty->driver_data;
+	struct gsm_mux *gsm = dlci->gsm;
+
+	dlci_put(dlci);
+	dlci_put(gsm->dlci[0]);
+	mux_put(gsm);
+	driver->ttys[tty->index] = NULL;
+}
 
 /* Virtual ttys for the demux */
 static const struct tty_operations gsmtty_ops = {
@@ -3172,6 +3184,7 @@ static const struct tty_operations gsmtty_ops = {
 	.tiocmget		= gsmtty_tiocmget,
 	.tiocmset		= gsmtty_tiocmset,
 	.break_ctl		= gsmtty_break_ctl,
+	.remove			= gsmtty_remove,
 };
 
 

drivers/tty/n_r3964.c

@@ -1244,7 +1244,7 @@ static void r3964_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 {
 	struct r3964_info *pInfo = tty->disc_data;
 	const unsigned char *p;
-	char *f, flags = 0;
+	char *f, flags = TTY_NORMAL;
 	int i;
 
 	for (i = count, p = cp, f = fp; i; i--, p++) {

drivers/tty/n_tty.c

@@ -105,6 +105,7 @@ struct n_tty_data {
 
 	/* must hold exclusive termios_rwsem to reset these */
 	unsigned char lnext:1, erasing:1, raw:1, real_raw:1, icanon:1;
+	unsigned char push:1;
 
 	/* shared by producer and consumer */
 	char read_buf[N_TTY_BUF_SIZE];
@@ -275,7 +276,8 @@ static void n_tty_check_unthrottle(struct tty_struct *tty)
 			return;
 		n_tty_set_room(tty);
 		n_tty_write_wakeup(tty->link);
-		wake_up_interruptible_poll(&tty->link->write_wait, POLLOUT);
+		if (waitqueue_active(&tty->link->write_wait))
+			wake_up_interruptible_poll(&tty->link->write_wait, POLLOUT);
 		return;
 	}
 
@@ -342,6 +344,7 @@ static void reset_buffer_flags(struct n_tty_data *ldata)
 
 	ldata->erasing = 0;
 	bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE);
+	ldata->push = 0;
 }
 
 static void n_tty_packet_mode_flush(struct tty_struct *tty)
@@ -351,7 +354,8 @@ static void n_tty_packet_mode_flush(struct tty_struct *tty)
 	spin_lock_irqsave(&tty->ctrl_lock, flags);
 	if (tty->link->packet) {
 		tty->ctrl_status |= TIOCPKT_FLUSHREAD;
-		wake_up_interruptible(&tty->link->read_wait);
+		if (waitqueue_active(&tty->link->read_wait))
+			wake_up_interruptible(&tty->link->read_wait);
 	}
 	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 }
@@ -1162,7 +1166,8 @@ static void n_tty_receive_break(struct tty_struct *tty)
 		put_tty_queue('\0', ldata);
 	}
 	put_tty_queue('\0', ldata);
-	wake_up_interruptible(&tty->read_wait);
+	if (waitqueue_active(&tty->read_wait))
+		wake_up_interruptible(&tty->read_wait);
 }
 
 /**
@@ -1220,7 +1225,8 @@ static void n_tty_receive_parity_error(struct tty_struct *tty, unsigned char c)
 		put_tty_queue('\0', ldata);
 	else
 		put_tty_queue(c, ldata);
-	wake_up_interruptible(&tty->read_wait);
+	if (waitqueue_active(&tty->read_wait))
+		wake_up_interruptible(&tty->read_wait);
 }
 
 static void
@@ -1264,7 +1270,6 @@ static int
 n_tty_receive_char_special(struct tty_struct *tty, unsigned char c)
 {
 	struct n_tty_data *ldata = tty->disc_data;
-	int parmrk;
 
 	if (I_IXON(tty)) {
 		if (c == START_CHAR(tty)) {
@@ -1349,8 +1354,6 @@ n_tty_receive_char_special(struct tty_struct *tty, unsigned char c)
 		}
 		if ((c == EOL_CHAR(tty)) ||
 		    (c == EOL2_CHAR(tty) && L_IEXTEN(tty))) {
-			parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty))
-				 ? 1 : 0;
 			/*
 			 * XXX are EOL_CHAR and EOL2_CHAR echoed?!?
 			 */
@@ -1365,7 +1368,7 @@ n_tty_receive_char_special(struct tty_struct *tty, unsigned char c)
 			 * XXX does PARMRK doubling happen for
 			 * EOL_CHAR and EOL2_CHAR?
 			 */
-			if (parmrk)
+			if (c == (unsigned char) '\377' && I_PARMRK(tty))
 				put_tty_queue(c, ldata);
 
 handle_newline:
@@ -1379,7 +1382,6 @@ handle_newline:
 		}
 	}
 
-	parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty)) ? 1 : 0;
 	if (L_ECHO(tty)) {
 		finish_erasing(ldata);
 		if (c == '\n')
@@ -1393,7 +1395,8 @@ handle_newline:
 		commit_echoes(tty);
 	}
 
-	if (parmrk)
+	/* PARMRK doubling check */
+	if (c == (unsigned char) '\377' && I_PARMRK(tty))
 		put_tty_queue(c, ldata);
 
 	put_tty_queue(c, ldata);
@@ -1404,7 +1407,6 @@ static inline void
 n_tty_receive_char_inline(struct tty_struct *tty, unsigned char c)
 {
 	struct n_tty_data *ldata = tty->disc_data;
-	int parmrk;
 
 	if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && I_IXANY(tty)) {
 		start_tty(tty);
@@ -1418,13 +1420,13 @@ n_tty_receive_char_inline(struct tty_struct *tty, unsigned char c)
 		echo_char(c, tty);
 		commit_echoes(tty);
 	}
-	parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty)) ? 1 : 0;
-	if (parmrk)
+	/* PARMRK doubling check */
+	if (c == (unsigned char) '\377' && I_PARMRK(tty))
 		put_tty_queue(c, ldata);
 	put_tty_queue(c, ldata);
 }
 
-static inline void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
+static void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
 {
 	n_tty_receive_char_inline(tty, c);
 }
@@ -1449,8 +1451,7 @@ n_tty_receive_char_fast(struct tty_struct *tty, unsigned char c)
 	put_tty_queue(c, ldata);
 }
 
-static inline void
-n_tty_receive_char_closing(struct tty_struct *tty, unsigned char c)
+static void n_tty_receive_char_closing(struct tty_struct *tty, unsigned char c)
 {
 	if (I_ISTRIP(tty))
 		c &= 0x7f;
@@ -1681,32 +1682,9 @@ static void __receive_buf(struct tty_struct *tty, const unsigned char *cp,
 	}
 }
 
-static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
-			      char *fp, int count)
-{
-	int room, n;
-
-	down_read(&tty->termios_rwsem);
-
-	while (1) {
-		room = receive_room(tty);
-		n = min(count, room);
-		if (!n)
-			break;
-		__receive_buf(tty, cp, fp, n);
-		cp += n;
-		if (fp)
-			fp += n;
-		count -= n;
-	}
-
-	tty->receive_room = room;
-	n_tty_check_throttle(tty);
-	up_read(&tty->termios_rwsem);
-}
-
-static int n_tty_receive_buf2(struct tty_struct *tty, const unsigned char *cp,
-			      char *fp, int count)
+static int
+n_tty_receive_buf_common(struct tty_struct *tty, const unsigned char *cp,
+			 char *fp, int count, int flow)
 {
 	struct n_tty_data *ldata = tty->disc_data;
 	int room, n, rcvd = 0;
@@ -1717,7 +1695,7 @@ static int n_tty_receive_buf2(struct tty_struct *tty, const unsigned char *cp,
 		room = receive_room(tty);
 		n = min(count, room);
 		if (!n) {
-			if (!room)
+			if (flow && !room)
 				ldata->no_room = 1;
 			break;
 		}
@@ -1736,6 +1714,18 @@ static int n_tty_receive_buf2(struct tty_struct *tty, const unsigned char *cp,
 	return rcvd;
 }
 
+static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+			      char *fp, int count)
+{
+	n_tty_receive_buf_common(tty, cp, fp, count, 0);
+}
+
+static int n_tty_receive_buf2(struct tty_struct *tty, const unsigned char *cp,
+			      char *fp, int count)
+{
+	return n_tty_receive_buf_common(tty, cp, fp, count, 1);
+}
+
 int is_ignored(int sig)
 {
 	return (sigismember(&current->blocked, sig) ||
@@ -1762,7 +1752,16 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
 
 	if (!old || (old->c_lflag ^ tty->termios.c_lflag) & ICANON) {
 		bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE);
-		ldata->line_start = ldata->canon_head = ldata->read_tail;
+		ldata->line_start = ldata->read_tail;
+		if (!L_ICANON(tty) || !read_cnt(ldata)) {
+			ldata->canon_head = ldata->read_tail;
+			ldata->push = 0;
+		} else {
+			set_bit((ldata->read_head - 1) & (N_TTY_BUF_SIZE - 1),
+				ldata->read_flags);
+			ldata->canon_head = ldata->read_head;
+			ldata->push = 1;
+		}
 		ldata->erasing = 0;
 		ldata->lnext = 0;
 	}
@@ -1825,8 +1824,10 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
 		start_tty(tty);
 
 	/* The termios change make the tty ready for I/O */
-	wake_up_interruptible(&tty->write_wait);
-	wake_up_interruptible(&tty->read_wait);
+	if (waitqueue_active(&tty->write_wait))
+		wake_up_interruptible(&tty->write_wait);
+	if (waitqueue_active(&tty->read_wait))
+		wake_up_interruptible(&tty->read_wait);
 }
 
 /**
@@ -1892,14 +1893,15 @@ err:
 	return -ENOMEM;
 }
 
-static inline int input_available_p(struct tty_struct *tty, int amt)
+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;
 
 	if (ldata->icanon && !L_EXTPROC(tty)) {
 		if (ldata->canon_head != ldata->read_tail)
 			return 1;
-	} else if (read_cnt(ldata) >= (amt ? amt : 1))
+	} else if (read_cnt(ldata) >= amt)
 		return 1;
 
 	return 0;
@@ -1965,6 +1967,12 @@ static int copy_from_read_buf(struct tty_struct *tty,
  *	it copies one line of input up to and including the line-delimiting
  *	character into the user-space buffer.
  *
+ *	NB: When termios is changed from non-canonical to canonical mode and
+ *	the read buffer contains data, n_tty_set_termios() simulates an EOF
+ *	push (as if C-d were input) _without_ the DISABLED_CHAR in the buffer.
+ *	This causes data already processed as input to be immediately available
+ *	as input although a newline has not been received.
+ *
  *	Called under the atomic_read_lock mutex
  *
  *	n_tty_read()/consumer path:
@@ -2011,7 +2019,7 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
 	n += found;
 	c = n;
 
-	if (found && read_buf(ldata, eol) == __DISABLED_CHAR) {
+	if (found && !ldata->push && read_buf(ldata, eol) == __DISABLED_CHAR) {
 		n--;
 		eof_push = !n && ldata->read_tail != ldata->line_start;
 	}
@@ -2038,7 +2046,10 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
 	ldata->read_tail += c;
 
 	if (found) {
-		ldata->line_start = ldata->read_tail;
+		if (!ldata->push)
+			ldata->line_start = ldata->read_tail;
+		else
+			ldata->push = 0;
 		tty_audit_push(tty);
 	}
 	return eof_push ? -EAGAIN : 0;
@@ -2398,7 +2409,7 @@ static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file,
 
 	poll_wait(file, &tty->read_wait, wait);
 	poll_wait(file, &tty->write_wait, wait);
-	if (input_available_p(tty, TIME_CHAR(tty) ? 0 : MIN_CHAR(tty)))
+	if (input_available_p(tty, 1))
 		mask |= POLLIN | POLLRDNORM;
 	if (tty->packet && tty->link->ctrl_status)
 		mask |= POLLPRI | POLLIN | POLLRDNORM;

drivers/tty/rocket.c

@@ -1744,7 +1744,7 @@ static void rp_flush_buffer(struct tty_struct *tty)
 
 #ifdef CONFIG_PCI
 
-static DEFINE_PCI_DEVICE_TABLE(rocket_pci_ids) = {
+static const struct pci_device_id rocket_pci_ids[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_RP, PCI_DEVICE_ID_RP4QUAD) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_RP, PCI_DEVICE_ID_RP8OCTA) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_RP, PCI_DEVICE_ID_URP8OCTA) },

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

@@ -2670,6 +2670,10 @@ static void serial8250_config_port(struct uart_port *port, int flags)
 	if (port->type == PORT_16550A && port->iotype == UPIO_AU)
 		up->bugs |= UART_BUG_NOMSR;
 
+	/* HW bugs may trigger IRQ while IIR == NO_INT */
+	if (port->type == PORT_TEGRA)
+		up->bugs |= UART_BUG_NOMSR;
+
 	if (port->type != PORT_UNKNOWN && flags & UART_CONFIG_IRQ)
 		autoconfig_irq(up);