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
  ...

3 files changed, 63 insertions, 132 deletions

diff --git a/drivers/staging/fwserial/Kconfig b/drivers/staging/fwserial/Kconfig
index a0812d99136..9c7c9267d52 100644
--- a/drivers/staging/fwserial/Kconfig
+++ b/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
diff --git a/drivers/staging/fwserial/fwserial.c b/drivers/staging/fwserial/fwserial.c
index 62df009e5ac..8af136e9c9d 100644
--- a/drivers/staging/fwserial/fwserial.c
+++ b/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);
diff --git a/drivers/staging/fwserial/fwserial.h b/drivers/staging/fwserial/fwserial.h
index 24635014a2a..54f7f9b9b21 100644
--- a/drivers/staging/fwserial/fwserial.h
+++ b/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