17 files changed, 140 insertions, 151 deletions

diff --git a/drivers/accessibility/speakup/serialio.c b/drivers/accessibility/speakup/serialio.c
index 403b01d66367..53580bdc5baa 100644
--- a/drivers/accessibility/speakup/serialio.c
+++ b/drivers/accessibility/speakup/serialio.c
@@ -27,11 +27,11 @@ static const struct old_serial_port *serstate;
 static int timeouts;
 
 static int spk_serial_out(struct spk_synth *in_synth, const char ch);
-static void spk_serial_send_xchar(char ch);
-static void spk_serial_tiocmset(unsigned int set, unsigned int clear);
-static unsigned char spk_serial_in(void);
-static unsigned char spk_serial_in_nowait(void);
-static void spk_serial_flush_buffer(void);
+static void spk_serial_send_xchar(struct spk_synth *in_synth, char ch);
+static void spk_serial_tiocmset(struct spk_synth *in_synth, unsigned int set, unsigned int clear);
+static unsigned char spk_serial_in(struct spk_synth *in_synth);
+static unsigned char spk_serial_in_nowait(struct spk_synth *in_synth);
+static void spk_serial_flush_buffer(struct spk_synth *in_synth);
 static int spk_serial_wait_for_xmitr(struct spk_synth *in_synth);
 
 struct spk_io_ops spk_serial_io_ops = {
@@ -150,7 +150,7 @@ static void start_serial_interrupt(int irq)
 	outb(1, speakup_info.port_tts + UART_FCR);	/* Turn FIFO On */
 }
 
-static void spk_serial_send_xchar(char ch)
+static void spk_serial_send_xchar(struct spk_synth *synth, char ch)
 {
 	int timeout = SPK_XMITR_TIMEOUT;
 
@@ -162,7 +162,7 @@ static void spk_serial_send_xchar(char ch)
 	outb(ch, speakup_info.port_tts);
 }
 
-static void spk_serial_tiocmset(unsigned int set, unsigned int clear)
+static void spk_serial_tiocmset(struct spk_synth *in_synth, unsigned int set, unsigned int clear)
 {
 	int old = inb(speakup_info.port_tts + UART_MCR);
 
@@ -251,7 +251,7 @@ static int spk_serial_wait_for_xmitr(struct spk_synth *in_synth)
 	return 1;
 }
 
-static unsigned char spk_serial_in(void)
+static unsigned char spk_serial_in(struct spk_synth *in_synth)
 {
 	int tmout = SPK_SERIAL_TIMEOUT;
 
@@ -265,7 +265,7 @@ static unsigned char spk_serial_in(void)
 	return inb_p(speakup_info.port_tts + UART_RX);
 }
 
-static unsigned char spk_serial_in_nowait(void)
+static unsigned char spk_serial_in_nowait(struct spk_synth *in_synth)
 {
 	unsigned char lsr;
 
@@ -275,7 +275,7 @@ static unsigned char spk_serial_in_nowait(void)
 	return inb_p(speakup_info.port_tts + UART_RX);
 }
 
-static void spk_serial_flush_buffer(void)
+static void spk_serial_flush_buffer(struct spk_synth *in_synth)
 {
 	/* TODO: flush the UART 16550 buffer */
 }
@@ -307,7 +307,7 @@ const char *spk_serial_synth_immediate(struct spk_synth *synth,
 }
 EXPORT_SYMBOL_GPL(spk_serial_synth_immediate);
 
-void spk_serial_release(void)
+void spk_serial_release(struct spk_synth *synth)
 {
 	spk_stop_serial_interrupt();
 	if (speakup_info.port_tts == 0)
diff --git a/drivers/accessibility/speakup/speakup_acntpc.c b/drivers/accessibility/speakup/speakup_acntpc.c
index c94328a5bd4a..c1ec087dca13 100644
--- a/drivers/accessibility/speakup/speakup_acntpc.c
+++ b/drivers/accessibility/speakup/speakup_acntpc.c
@@ -25,7 +25,7 @@
 #define PROCSPEECH '\r'
 
 static int synth_probe(struct spk_synth *synth);
-static void accent_release(void);
+static void accent_release(struct spk_synth *synth);
 static const char *synth_immediate(struct spk_synth *synth, const char *buf);
 static void do_catch_up(struct spk_synth *synth);
 static void synth_flush(struct spk_synth *synth);
@@ -294,7 +294,7 @@ static int synth_probe(struct spk_synth *synth)
 	return 0;
 }
 
-static void accent_release(void)
+static void accent_release(struct spk_synth *synth)
 {
 	spk_stop_serial_interrupt();
 	if (speakup_info.port_tts)
diff --git a/drivers/accessibility/speakup/speakup_apollo.c b/drivers/accessibility/speakup/speakup_apollo.c
index 0877b4044c28..cd63581b2e99 100644
--- a/drivers/accessibility/speakup/speakup_apollo.c
+++ b/drivers/accessibility/speakup/speakup_apollo.c
@@ -163,8 +163,8 @@ static void do_catch_up(struct spk_synth *synth)
 		full_time_val = full_time->u.n.value;
 		spin_unlock_irqrestore(&speakup_info.spinlock, flags);
 		if (!synth->io_ops->synth_out(synth, ch)) {
-			synth->io_ops->tiocmset(0, UART_MCR_RTS);
-			synth->io_ops->tiocmset(UART_MCR_RTS, 0);
+			synth->io_ops->tiocmset(synth, 0, UART_MCR_RTS);
+			synth->io_ops->tiocmset(synth, UART_MCR_RTS, 0);
 			schedule_timeout(msecs_to_jiffies(full_time_val));
 			continue;
 		}
diff --git a/drivers/accessibility/speakup/speakup_audptr.c b/drivers/accessibility/speakup/speakup_audptr.c
index e6a6a9665d8f..e89fd72579e6 100644
--- a/drivers/accessibility/speakup/speakup_audptr.c
+++ b/drivers/accessibility/speakup/speakup_audptr.c
@@ -119,8 +119,8 @@ static struct spk_synth synth_audptr = {
 
 static void synth_flush(struct spk_synth *synth)
 {
-	synth->io_ops->flush_buffer();
-	synth->io_ops->send_xchar(SYNTH_CLEAR);
+	synth->io_ops->flush_buffer(synth);
+	synth->io_ops->send_xchar(synth, SYNTH_CLEAR);
 	synth->io_ops->synth_out(synth, PROCSPEECH);
 }
 
@@ -130,11 +130,11 @@ static void synth_version(struct spk_synth *synth)
 	char synth_id[40] = "";
 
 	synth->synth_immediate(synth, "\x05[Q]");
-	synth_id[test] = synth->io_ops->synth_in();
+	synth_id[test] = synth->io_ops->synth_in(synth);
 	if (synth_id[test] == 'A') {
 		do {
 			/* read version string from synth */
-			synth_id[++test] = synth->io_ops->synth_in();
+			synth_id[++test] = synth->io_ops->synth_in(synth);
 		} while (synth_id[test] != '\n' && test < 32);
 		synth_id[++test] = 0x00;
 	}
diff --git a/drivers/accessibility/speakup/speakup_decext.c b/drivers/accessibility/speakup/speakup_decext.c
index 7408eb29cf38..092cfd08a9e1 100644
--- a/drivers/accessibility/speakup/speakup_decext.c
+++ b/drivers/accessibility/speakup/speakup_decext.c
@@ -218,7 +218,7 @@ static void do_catch_up(struct spk_synth *synth)
 static void synth_flush(struct spk_synth *synth)
 {
 	in_escape = 0;
-	synth->io_ops->flush_buffer();
+	synth->io_ops->flush_buffer(synth);
 	synth->synth_immediate(synth, "\033P;10z\033\\");
 }
 
diff --git a/drivers/accessibility/speakup/speakup_decpc.c b/drivers/accessibility/speakup/speakup_decpc.c
index 96f24c848cc5..dec314dee214 100644
--- a/drivers/accessibility/speakup/speakup_decpc.c
+++ b/drivers/accessibility/speakup/speakup_decpc.c
@@ -125,7 +125,7 @@ enum {	PRIMARY_DIC	= 0, USER_DIC, COMMAND_DIC, ABBREV_DIC };
 #define SYNTH_IO_EXTENT 8
 
 static int synth_probe(struct spk_synth *synth);
-static void dtpc_release(void);
+static void dtpc_release(struct spk_synth *synth);
 static const char *synth_immediate(struct spk_synth *synth, const char *buf);
 static void do_catch_up(struct spk_synth *synth);
 static void synth_flush(struct spk_synth *synth);
@@ -474,7 +474,7 @@ static int synth_probe(struct spk_synth *synth)
 	return 0;
 }
 
-static void dtpc_release(void)
+static void dtpc_release(struct spk_synth *synth)
 {
 	spk_stop_serial_interrupt();
 	if (speakup_info.port_tts)
diff --git a/drivers/accessibility/speakup/speakup_dectlk.c b/drivers/accessibility/speakup/speakup_dectlk.c
index ab6d61e80b1c..580ec796816b 100644
--- a/drivers/accessibility/speakup/speakup_dectlk.c
+++ b/drivers/accessibility/speakup/speakup_dectlk.c
@@ -78,6 +78,8 @@ static struct kobj_attribute direct_attribute =
 	__ATTR(direct, 0644, spk_var_show, spk_var_store);
 static struct kobj_attribute full_time_attribute =
 	__ATTR(full_time, 0644, spk_var_show, spk_var_store);
+static struct kobj_attribute flush_time_attribute =
+	__ATTR(flush_time, 0644, spk_var_show, spk_var_store);
 static struct kobj_attribute jiffy_delta_attribute =
 	__ATTR(jiffy_delta, 0644, spk_var_show, spk_var_store);
 static struct kobj_attribute trigger_time_attribute =
@@ -99,6 +101,7 @@ static struct attribute *synth_attrs[] = {
 	&delay_time_attribute.attr,
 	&direct_attribute.attr,
 	&full_time_attribute.attr,
+	&flush_time_attribute.attr,
 	&jiffy_delta_attribute.attr,
 	&trigger_time_attribute.attr,
 	NULL,	/* need to NULL terminate the list of attributes */
@@ -118,6 +121,7 @@ static struct spk_synth synth_dectlk = {
 	.trigger = 50,
 	.jiffies = 50,
 	.full = 40000,
+	.flush_time = 4000,
 	.dev_name = SYNTH_DEFAULT_DEV,
 	.startup = SYNTH_START,
 	.checkval = SYNTH_CHECK,
@@ -200,18 +204,23 @@ static void do_catch_up(struct spk_synth *synth)
 	static u_char last = '\0';
 	unsigned long flags;
 	unsigned long jiff_max;
-	unsigned long timeout = msecs_to_jiffies(4000);
+	unsigned long timeout;
 	DEFINE_WAIT(wait);
 	struct var_t *jiffy_delta;
 	struct var_t *delay_time;
+	struct var_t *flush_time;
 	int jiffy_delta_val;
 	int delay_time_val;
+	int timeout_val;
 
 	jiffy_delta = spk_get_var(JIFFY);
 	delay_time = spk_get_var(DELAY);
+	flush_time = spk_get_var(FLUSH);
 	spin_lock_irqsave(&speakup_info.spinlock, flags);
 	jiffy_delta_val = jiffy_delta->u.n.value;
+	timeout_val = flush_time->u.n.value;
 	spin_unlock_irqrestore(&speakup_info.spinlock, flags);
+	timeout = msecs_to_jiffies(timeout_val);
 	jiff_max = jiffies + jiffy_delta_val;
 
 	while (!kthread_should_stop()) {
@@ -289,7 +298,7 @@ static void synth_flush(struct spk_synth *synth)
 		synth->io_ops->synth_out(synth, ']');
 	in_escape = 0;
 	is_flushing = 1;
-	synth->io_ops->flush_buffer();
+	synth->io_ops->flush_buffer(synth);
 	synth->io_ops->synth_out(synth, SYNTH_CLEAR);
 }
 
diff --git a/drivers/accessibility/speakup/speakup_dtlk.c b/drivers/accessibility/speakup/speakup_dtlk.c
index dbebed0eeeec..92838d3ae9eb 100644
--- a/drivers/accessibility/speakup/speakup_dtlk.c
+++ b/drivers/accessibility/speakup/speakup_dtlk.c
@@ -24,7 +24,7 @@
 #define PROCSPEECH 0x00
 
 static int synth_probe(struct spk_synth *synth);
-static void dtlk_release(void);
+static void dtlk_release(struct spk_synth *synth);
 static const char *synth_immediate(struct spk_synth *synth, const char *buf);
 static void do_catch_up(struct spk_synth *synth);
 static void synth_flush(struct spk_synth *synth);
@@ -365,7 +365,7 @@ static int synth_probe(struct spk_synth *synth)
 	return 0;
 }
 
-static void dtlk_release(void)
+static void dtlk_release(struct spk_synth *synth)
 {
 	spk_stop_serial_interrupt();
 	if (speakup_info.port_tts)
diff --git a/drivers/accessibility/speakup/speakup_keypc.c b/drivers/accessibility/speakup/speakup_keypc.c
index 414827e888fc..311f4aa0be22 100644
--- a/drivers/accessibility/speakup/speakup_keypc.c
+++ b/drivers/accessibility/speakup/speakup_keypc.c
@@ -24,7 +24,7 @@
 #define SYNTH_CLEAR 0x03
 
 static int synth_probe(struct spk_synth *synth);
-static void keynote_release(void);
+static void keynote_release(struct spk_synth *synth);
 static const char *synth_immediate(struct spk_synth *synth, const char *buf);
 static void do_catch_up(struct spk_synth *synth);
 static void synth_flush(struct spk_synth *synth);
@@ -295,7 +295,7 @@ static int synth_probe(struct spk_synth *synth)
 	return 0;
 }
 
-static void keynote_release(void)
+static void keynote_release(struct spk_synth *synth)
 {
 	spk_stop_serial_interrupt();
 	if (synth_port)
diff --git a/drivers/accessibility/speakup/speakup_ltlk.c b/drivers/accessibility/speakup/speakup_ltlk.c
index 3c59519a871f..3e59b387d0c4 100644
--- a/drivers/accessibility/speakup/speakup_ltlk.c
+++ b/drivers/accessibility/speakup/speakup_ltlk.c
@@ -132,7 +132,7 @@ static void synth_interrogate(struct spk_synth *synth)
 
 	synth->synth_immediate(synth, "\x18\x01?");
 	for (i = 0; i < 50; i++) {
-		buf[i] = synth->io_ops->synth_in();
+		buf[i] = synth->io_ops->synth_in(synth);
 		if (i > 2 && buf[i] == 0x7f)
 			break;
 	}
diff --git a/drivers/accessibility/speakup/speakup_soft.c b/drivers/accessibility/speakup/speakup_soft.c
index 9a7029539f35..c3f97c572fb6 100644
--- a/drivers/accessibility/speakup/speakup_soft.c
+++ b/drivers/accessibility/speakup/speakup_soft.c
@@ -24,7 +24,7 @@
 #define CLEAR_SYNTH 0x18
 
 static int softsynth_probe(struct spk_synth *synth);
-static void softsynth_release(void);
+static void softsynth_release(struct spk_synth *synth);
 static int softsynth_is_alive(struct spk_synth *synth);
 static unsigned char get_index(struct spk_synth *synth);
 
@@ -402,7 +402,7 @@ static int softsynth_probe(struct spk_synth *synth)
 	return 0;
 }
 
-static void softsynth_release(void)
+static void softsynth_release(struct spk_synth *synth)
 {
 	misc_deregister(&synth_device);
 	misc_deregister(&synthu_device);
diff --git a/drivers/accessibility/speakup/speakup_spkout.c b/drivers/accessibility/speakup/speakup_spkout.c
index 6e933bf1de2e..bd3d8dc300ff 100644
--- a/drivers/accessibility/speakup/speakup_spkout.c
+++ b/drivers/accessibility/speakup/speakup_spkout.c
@@ -117,8 +117,8 @@ static struct spk_synth synth_spkout = {
 
 static void synth_flush(struct spk_synth *synth)
 {
-	synth->io_ops->flush_buffer();
-	synth->io_ops->send_xchar(SYNTH_CLEAR);
+	synth->io_ops->flush_buffer(synth);
+	synth->io_ops->send_xchar(synth, SYNTH_CLEAR);
 }
 
 module_param_named(ser, synth_spkout.ser, int, 0444);
diff --git a/drivers/accessibility/speakup/spk_priv.h b/drivers/accessibility/speakup/spk_priv.h
index 0f4bcbe5ddb9..9da57ead17cb 100644
--- a/drivers/accessibility/speakup/spk_priv.h
+++ b/drivers/accessibility/speakup/spk_priv.h
@@ -34,8 +34,8 @@
 
 const struct old_serial_port *spk_serial_init(int index);
 void spk_stop_serial_interrupt(void);
-void spk_serial_release(void);
-void spk_ttyio_release(void);
+void spk_serial_release(struct spk_synth *synth);
+void spk_ttyio_release(struct spk_synth *synth);
 void spk_ttyio_register_ldisc(void);
 void spk_ttyio_unregister_ldisc(void);
 
diff --git a/drivers/accessibility/speakup/spk_ttyio.c b/drivers/accessibility/speakup/spk_ttyio.c
index 835d17455fcd..9af1d4c124d3 100644
--- a/drivers/accessibility/speakup/spk_ttyio.c
+++ b/drivers/accessibility/speakup/spk_ttyio.c
@@ -12,14 +12,15 @@ struct spk_ldisc_data {
 	char buf;
 	struct completion completion;
 	bool buf_free;
+	struct spk_synth *synth;
 };
 
-static struct spk_synth *spk_ttyio_synth;
-static struct tty_struct *speakup_tty;
-/* mutex to protect against speakup_tty disappearing from underneath us while
- * we are using it. this can happen when the device physically unplugged,
- * while in use. it also serialises access to speakup_tty.
+/*
+ * This allows to catch within spk_ttyio_ldisc_open whether it is getting set
+ * on for a speakup-driven device.
  */
+static struct tty_struct *speakup_tty;
+/* This mutex serializes the use of such global speakup_tty variable */
 static DEFINE_MUTEX(speakup_tty_mutex);
 
 static int ser_to_dev(int ser, dev_t *dev_no)
@@ -67,22 +68,20 @@ static int spk_ttyio_ldisc_open(struct tty_struct *tty)
 
 static void spk_ttyio_ldisc_close(struct tty_struct *tty)
 {
-	mutex_lock(&speakup_tty_mutex);
-	kfree(speakup_tty->disc_data);
-	speakup_tty = NULL;
-	mutex_unlock(&speakup_tty_mutex);
+	kfree(tty->disc_data);
 }
 
 static int spk_ttyio_receive_buf2(struct tty_struct *tty,
 				  const unsigned char *cp, char *fp, int count)
 {
 	struct spk_ldisc_data *ldisc_data = tty->disc_data;
+	struct spk_synth *synth = ldisc_data->synth;
 
-	if (spk_ttyio_synth->read_buff_add) {
+	if (synth->read_buff_add) {
 		int i;
 
 		for (i = 0; i < count; i++)
-			spk_ttyio_synth->read_buff_add(cp[i]);
+			synth->read_buff_add(cp[i]);
 
 		return count;
 	}
@@ -114,11 +113,11 @@ static struct tty_ldisc_ops spk_ttyio_ldisc_ops = {
 
 static int spk_ttyio_out(struct spk_synth *in_synth, const char ch);
 static int spk_ttyio_out_unicode(struct spk_synth *in_synth, u16 ch);
-static void spk_ttyio_send_xchar(char ch);
-static void spk_ttyio_tiocmset(unsigned int set, unsigned int clear);
-static unsigned char spk_ttyio_in(void);
-static unsigned char spk_ttyio_in_nowait(void);
-static void spk_ttyio_flush_buffer(void);
+static void spk_ttyio_send_xchar(struct spk_synth *in_synth, char ch);
+static void spk_ttyio_tiocmset(struct spk_synth *in_synth, unsigned int set, unsigned int clear);
+static unsigned char spk_ttyio_in(struct spk_synth *in_synth);
+static unsigned char spk_ttyio_in_nowait(struct spk_synth *in_synth);
+static void spk_ttyio_flush_buffer(struct spk_synth *in_synth);
 static int spk_ttyio_wait_for_xmitr(struct spk_synth *in_synth);
 
 struct spk_io_ops spk_ttyio_ops = {
@@ -187,13 +186,17 @@ static int spk_ttyio_initialise_ldisc(struct spk_synth *synth)
 	mutex_lock(&speakup_tty_mutex);
 	speakup_tty = tty;
 	ret = tty_set_ldisc(tty, N_SPEAKUP);
-	if (ret)
-		speakup_tty = NULL;
+	speakup_tty = NULL;
 	mutex_unlock(&speakup_tty_mutex);
 
-	if (!ret)
+	if (!ret) {
 		/* Success */
+		struct spk_ldisc_data *ldisc_data = tty->disc_data;
+
+		ldisc_data->synth = synth;
+		synth->dev = tty;
 		return 0;
+	}
 
 	pr_err("speakup: Failed to set N_SPEAKUP on tty\n");
 
@@ -221,29 +224,30 @@ void spk_ttyio_unregister_ldisc(void)
 
 static int spk_ttyio_out(struct spk_synth *in_synth, const char ch)
 {
-	mutex_lock(&speakup_tty_mutex);
-	if (in_synth->alive && speakup_tty && speakup_tty->ops->write) {
-		int ret = speakup_tty->ops->write(speakup_tty, &ch, 1);
-
-		mutex_unlock(&speakup_tty_mutex);
-		if (ret == 0)
-			/* No room */
-			return 0;
-		if (ret < 0) {
-			pr_warn("%s: I/O error, deactivating speakup\n",
-				in_synth->long_name);
-			/* No synth any more, so nobody will restart TTYs,
-			 * and we thus need to do it ourselves.  Now that there
-			 * is no synth we can let application flood anyway
-			 */
-			in_synth->alive = 0;
-			speakup_start_ttys();
-			return 0;
-		}
+	struct tty_struct *tty = in_synth->dev;
+	int ret;
+
+	if (!in_synth->alive || !tty->ops->write)
+		return 0;
+
+	ret = tty->ops->write(tty, &ch, 1);
+
+	if (ret == 0)
+		/* No room */
+		return 0;
+
+	if (ret > 0)
+		/* Success */
 		return 1;
-	}
 
-	mutex_unlock(&speakup_tty_mutex);
+	pr_warn("%s: I/O error, deactivating speakup\n",
+		in_synth->long_name);
+	/* No synth any more, so nobody will restart TTYs,
+	 * and we thus need to do it ourselves.  Now that there
+	 * is no synth we can let application flood anyway
+	 */
+	in_synth->alive = 0;
+	speakup_start_ttys();
 	return 0;
 }
 
@@ -264,47 +268,20 @@ static int spk_ttyio_out_unicode(struct spk_synth *in_synth, u16 ch)
 	return ret;
 }
 
-static int check_tty(struct tty_struct *tty)
-{
-	if (!tty) {
-		pr_warn("%s: I/O error, deactivating speakup\n",
-			spk_ttyio_synth->long_name);
-		/* No synth any more, so nobody will restart TTYs, and we thus
-		 * need to do it ourselves.  Now that there is no synth we can
-		 * let application flood anyway
-		 */
-		spk_ttyio_synth->alive = 0;
-		speakup_start_ttys();
-		return 1;
-	}
-
-	return 0;
-}
-
-static void spk_ttyio_send_xchar(char ch)
+static void spk_ttyio_send_xchar(struct spk_synth *in_synth, char ch)
 {
-	mutex_lock(&speakup_tty_mutex);
-	if (check_tty(speakup_tty)) {
-		mutex_unlock(&speakup_tty_mutex);
-		return;
-	}
+	struct tty_struct *tty = in_synth->dev;
 
-	if (speakup_tty->ops->send_xchar)
-		speakup_tty->ops->send_xchar(speakup_tty, ch);
-	mutex_unlock(&speakup_tty_mutex);
+	if (tty->ops->send_xchar)
+		tty->ops->send_xchar(tty, ch);
 }
 
-static void spk_ttyio_tiocmset(unsigned int set, unsigned int clear)
+static void spk_ttyio_tiocmset(struct spk_synth *in_synth, unsigned int set, unsigned int clear)
 {
-	mutex_lock(&speakup_tty_mutex);
-	if (check_tty(speakup_tty)) {
-		mutex_unlock(&speakup_tty_mutex);
-		return;
-	}
+	struct tty_struct *tty = in_synth->dev;
 
-	if (speakup_tty->ops->tiocmset)
-		speakup_tty->ops->tiocmset(speakup_tty, set, clear);
-	mutex_unlock(&speakup_tty_mutex);
+	if (tty->ops->tiocmset)
+		tty->ops->tiocmset(tty, set, clear);
 }
 
 static int spk_ttyio_wait_for_xmitr(struct spk_synth *in_synth)
@@ -312,9 +289,10 @@ static int spk_ttyio_wait_for_xmitr(struct spk_synth *in_synth)
 	return 1;
 }
 
-static unsigned char ttyio_in(int timeout)
+static unsigned char ttyio_in(struct spk_synth *in_synth, int timeout)
 {
-	struct spk_ldisc_data *ldisc_data = speakup_tty->disc_data;
+	struct tty_struct *tty = in_synth->dev;
+	struct spk_ldisc_data *ldisc_data = tty->disc_data;
 	char rv;
 
 	if (!timeout) {
@@ -334,35 +312,29 @@ static unsigned char ttyio_in(int timeout)
 	mb();
 	ldisc_data->buf_free = true;
 	/* Let TTY push more characters */
-	tty_schedule_flip(speakup_tty->port);
+	tty_schedule_flip(tty->port);
 
 	return rv;
 }
 
-static unsigned char spk_ttyio_in(void)
+static unsigned char spk_ttyio_in(struct spk_synth *in_synth)
 {
-	return ttyio_in(SPK_SYNTH_TIMEOUT);
+	return ttyio_in(in_synth, SPK_SYNTH_TIMEOUT);
 }
 
-static unsigned char spk_ttyio_in_nowait(void)
+static unsigned char spk_ttyio_in_nowait(struct spk_synth *in_synth)
 {
-	u8 rv = ttyio_in(0);
+	u8 rv = ttyio_in(in_synth, 0);
 
 	return (rv == 0xff) ? 0 : rv;
 }
 
-static void spk_ttyio_flush_buffer(void)
+static void spk_ttyio_flush_buffer(struct spk_synth *in_synth)
 {
-	mutex_lock(&speakup_tty_mutex);
-	if (check_tty(speakup_tty)) {
-		mutex_unlock(&speakup_tty_mutex);
-		return;
-	}
+	struct tty_struct *tty = in_synth->dev;
 
-	if (speakup_tty->ops->flush_buffer)
-		speakup_tty->ops->flush_buffer(speakup_tty);
-
-	mutex_unlock(&speakup_tty_mutex);
+	if (tty->ops->flush_buffer)
+		tty->ops->flush_buffer(tty);
 }
 
 int spk_ttyio_synth_probe(struct spk_synth *synth)
@@ -373,37 +345,38 @@ int spk_ttyio_synth_probe(struct spk_synth *synth)
 		return rv;
 
 	synth->alive = 1;
-	spk_ttyio_synth = synth;
 
 	return 0;
 }
 EXPORT_SYMBOL_GPL(spk_ttyio_synth_probe);
 
-void spk_ttyio_release(void)
+void spk_ttyio_release(struct spk_synth *in_synth)
 {
-	if (!speakup_tty)
-		return;
+	struct tty_struct *tty = in_synth->dev;
 
-	tty_lock(speakup_tty);
+	tty_lock(tty);
 
-	if (speakup_tty->ops->close)
-		speakup_tty->ops->close(speakup_tty, NULL);
+	if (tty->ops->close)
+		tty->ops->close(tty, NULL);
+
+	tty_ldisc_flush(tty);
+	tty_unlock(tty);
+	tty_kclose(tty);
 
-	tty_ldisc_flush(speakup_tty);
-	tty_unlock(speakup_tty);
-	tty_kclose(speakup_tty);
+	in_synth->dev = NULL;
 }
 EXPORT_SYMBOL_GPL(spk_ttyio_release);
 
-const char *spk_ttyio_synth_immediate(struct spk_synth *synth, const char *buff)
+const char *spk_ttyio_synth_immediate(struct spk_synth *in_synth, const char *buff)
 {
+	struct tty_struct *tty = in_synth->dev;
 	u_char ch;
 
 	while ((ch = *buff)) {
 		if (ch == '\n')
-			ch = synth->procspeech;
-		if (tty_write_room(speakup_tty) < 1 ||
-		    !synth->io_ops->synth_out(synth, ch))
+			ch = in_synth->procspeech;
+		if (tty_write_room(tty) < 1 ||
+		    !in_synth->io_ops->synth_out(in_synth, ch))
 			return buff;
 		buff++;
 	}
diff --git a/drivers/accessibility/speakup/spk_types.h b/drivers/accessibility/speakup/spk_types.h
index 91fca3033a45..6a96ad94bc3f 100644
--- a/drivers/accessibility/speakup/spk_types.h
+++ b/drivers/accessibility/speakup/spk_types.h
@@ -48,7 +48,7 @@ enum var_id_t {
 	ATTRIB_BLEEP, BLEEPS,
 	RATE, PITCH, VOL, TONE, PUNCT, VOICE, FREQUENCY, LANG,
 	DIRECT, PAUSE,
-	CAPS_START, CAPS_STOP, CHARTAB, INFLECTION,
+	CAPS_START, CAPS_STOP, CHARTAB, INFLECTION, FLUSH,
 	MAXVARS
 };
 
@@ -157,11 +157,11 @@ struct spk_synth;
 struct spk_io_ops {
 	int (*synth_out)(struct spk_synth *synth, const char ch);
 	int (*synth_out_unicode)(struct spk_synth *synth, u16 ch);
-	void (*send_xchar)(char ch);
-	void (*tiocmset)(unsigned int set, unsigned int clear);
-	unsigned char (*synth_in)(void);
-	unsigned char (*synth_in_nowait)(void);
-	void (*flush_buffer)(void);
+	void (*send_xchar)(struct spk_synth *synth, char ch);
+	void (*tiocmset)(struct spk_synth *synth, unsigned int set, unsigned int clear);
+	unsigned char (*synth_in)(struct spk_synth *synth);
+	unsigned char (*synth_in_nowait)(struct spk_synth *synth);
+	void (*flush_buffer)(struct spk_synth *synth);
 	int (*wait_for_xmitr)(struct spk_synth *synth);
 };
 
@@ -178,6 +178,7 @@ struct spk_synth {
 	int trigger;
 	int jiffies;
 	int full;
+	int flush_time;
 	int ser;
 	char *dev_name;
 	short flags;
@@ -188,7 +189,7 @@ struct spk_synth {
 	int *default_vol;
 	struct spk_io_ops *io_ops;
 	int (*probe)(struct spk_synth *synth);
-	void (*release)(void);
+	void (*release)(struct spk_synth *synth);
 	const char *(*synth_immediate)(struct spk_synth *synth,
 				       const char *buff);
 	void (*catch_up)(struct spk_synth *synth);
@@ -200,6 +201,8 @@ struct spk_synth {
 	struct synth_indexing indexing;
 	int alive;
 	struct attribute_group attributes;
+
+	void *dev;
 };
 
 /*
diff --git a/drivers/accessibility/speakup/synth.c b/drivers/accessibility/speakup/synth.c
index ac47dbac7207..2b8699673bac 100644
--- a/drivers/accessibility/speakup/synth.c
+++ b/drivers/accessibility/speakup/synth.c
@@ -137,14 +137,14 @@ EXPORT_SYMBOL_GPL(spk_do_catch_up_unicode);
 
 void spk_synth_flush(struct spk_synth *synth)
 {
-	synth->io_ops->flush_buffer();
+	synth->io_ops->flush_buffer(synth);
 	synth->io_ops->synth_out(synth, synth->clear);
 }
 EXPORT_SYMBOL_GPL(spk_synth_flush);
 
 unsigned char spk_synth_get_index(struct spk_synth *synth)
 {
-	return synth->io_ops->synth_in_nowait();
+	return synth->io_ops->synth_in_nowait(synth);
 }
 EXPORT_SYMBOL_GPL(spk_synth_get_index);
 
@@ -348,6 +348,7 @@ struct var_t synth_time_vars[] = {
 	{ TRIGGER, .u.n = {NULL, 20, 10, 2000, 0, 0, NULL } },
 	{ JIFFY, .u.n = {NULL, 50, 20, 200, 0, 0, NULL } },
 	{ FULL, .u.n = {NULL, 400, 200, 60000, 0, 0, NULL } },
+	{ FLUSH, .u.n = {NULL, 4000, 100, 4000, 0, 0, NULL } },
 	V_LAST_VAR
 };
 
@@ -408,6 +409,8 @@ static int do_synth_init(struct spk_synth *in_synth)
 		synth_time_vars[2].u.n.default_val = synth->jiffies;
 	synth_time_vars[3].u.n.value =
 		synth_time_vars[3].u.n.default_val = synth->full;
+	synth_time_vars[4].u.n.value =
+		synth_time_vars[4].u.n.default_val = synth->flush_time;
 	synth_printf("%s", synth->init);
 	for (var = synth->vars;
 		(var->var_id >= 0) && (var->var_id < MAXVARS); var++)
@@ -440,7 +443,7 @@ void synth_release(void)
 		sysfs_remove_group(speakup_kobj, &synth->attributes);
 	for (var = synth->vars; var->var_id != MAXVARS; var++)
 		speakup_unregister_var(var->var_id);
-	synth->release();
+	synth->release(synth);
 	synth = NULL;
 }
 
diff --git a/drivers/accessibility/speakup/varhandlers.c b/drivers/accessibility/speakup/varhandlers.c
index d7f6bec7ff06..067c0da97dcb 100644
--- a/drivers/accessibility/speakup/varhandlers.c
+++ b/drivers/accessibility/speakup/varhandlers.c
@@ -23,6 +23,7 @@ static struct st_var_header var_headers[] = {
 	{ "trigger_time", TRIGGER, VAR_TIME, NULL, NULL },
 	{ "jiffy_delta", JIFFY, VAR_TIME, NULL, NULL },
 	{ "full_time", FULL, VAR_TIME, NULL, NULL },
+	{ "flush_time", FLUSH, VAR_TIME, NULL, NULL },
 	{ "spell_delay", SPELL_DELAY, VAR_NUM, &spk_spell_delay, NULL },
 	{ "bleeps", BLEEPS, VAR_NUM, &spk_bleeps, NULL },
 	{ "attrib_bleep", ATTRIB_BLEEP, VAR_NUM, &spk_attrib_bleep, NULL },