8 files changed, 48 insertions, 14 deletions

diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c
index 2b86f8e0fb58..71630a2af42c 100644
--- a/drivers/tty/amiserial.c
+++ b/drivers/tty/amiserial.c
@@ -1855,6 +1855,9 @@ static struct console sercons = {
  */
 static int __init amiserial_console_init(void)
 {
+        if (!MACH_IS_AMIGA)
+                return -ENODEV;
+
         register_console(&sercons);
         return 0;
 }
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 7cdd1eb9406c..34aacaaae14a 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -93,6 +93,7 @@ struct n_tty_data {
         size_t canon_head;
         size_t echo_head;
         size_t echo_commit;
+        size_t echo_mark;
         DECLARE_BITMAP(char_map, 256);
 
         /* private to n_tty_receive_overrun (single-threaded) */
@@ -336,6 +337,7 @@ static void reset_buffer_flags(struct n_tty_data *ldata)
 {
         ldata->read_head = ldata->canon_head = ldata->read_tail = 0;
         ldata->echo_head = ldata->echo_tail = ldata->echo_commit = 0;
+        ldata->echo_mark = 0;
         ldata->line_start = 0;
 
         ldata->erasing = 0;
@@ -768,7 +770,7 @@ static size_t __process_echoes(struct tty_struct *tty)
          * data at the tail to prevent a subsequent overrun */
         while (ldata->echo_commit - tail >= ECHO_DISCARD_WATERMARK) {
                 if (echo_buf(ldata, tail) == ECHO_OP_START) {
-                        if (echo_buf(ldata, tail) == ECHO_OP_ERASE_TAB)
+                        if (echo_buf(ldata, tail + 1) == ECHO_OP_ERASE_TAB)
                                 tail += 3;
                         else
                                 tail += 2;
@@ -787,6 +789,7 @@ static void commit_echoes(struct tty_struct *tty)
         size_t head;
 
         head = ldata->echo_head;
+        ldata->echo_mark = head;
         old = ldata->echo_commit - ldata->echo_tail;
 
         /* Process committed echoes if the accumulated # of bytes
@@ -810,10 +813,12 @@ static void process_echoes(struct tty_struct *tty)
         struct n_tty_data *ldata = tty->disc_data;
         size_t echoed;
 
-        if (!L_ECHO(tty) || ldata->echo_commit == ldata->echo_tail)
+        if ((!L_ECHO(tty) && !L_ECHONL(tty)) ||
+            ldata->echo_mark == ldata->echo_tail)
                 return;
 
         mutex_lock(&ldata->output_lock);
+        ldata->echo_commit = ldata->echo_mark;
         echoed = __process_echoes(tty);
         mutex_unlock(&ldata->output_lock);
 
@@ -821,11 +826,13 @@ static void process_echoes(struct tty_struct *tty)
                 tty->ops->flush_chars(tty);
 }
 
+/* NB: echo_mark and echo_head should be equivalent here */
 static void flush_echoes(struct tty_struct *tty)
 {
         struct n_tty_data *ldata = tty->disc_data;
 
-        if (!L_ECHO(tty) || ldata->echo_commit == ldata->echo_head)
+        if ((!L_ECHO(tty) && !L_ECHONL(tty)) ||
+            ldata->echo_commit == ldata->echo_head)
                 return;
 
         mutex_lock(&ldata->output_lock);
@@ -1998,7 +2005,10 @@ static int canon_copy_from_read_buf(struct tty_struct *tty,
                 found = 1;
 
         size = N_TTY_BUF_SIZE - tail;
-        n = (found + eol + size) & (N_TTY_BUF_SIZE - 1);
+        n = eol - tail;
+        if (n > 4096)
+                n += 4096;
+        n += found;
         c = n;
 
         if (found && read_buf(ldata, eol) == __DISABLED_CHAR) {
@@ -2243,18 +2253,19 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
                 if (time)
                         timeout = time;
         }
-        mutex_unlock(&ldata->atomic_read_lock);
-        remove_wait_queue(&tty->read_wait, &wait);
+        n_tty_set_room(tty);
+        up_read(&tty->termios_rwsem);
 
+        remove_wait_queue(&tty->read_wait, &wait);
         if (!waitqueue_active(&tty->read_wait))
                 ldata->minimum_to_wake = minimum;
 
+        mutex_unlock(&ldata->atomic_read_lock);
+
         __set_current_state(TASK_RUNNING);
         if (b - buf)
                 retval = b - buf;
 
-        n_tty_set_room(tty);
-        up_read(&tty->termios_rwsem);
         return retval;
 }
 
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 4658e3e0ec42..06525f10e364 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -96,7 +96,8 @@ static void dw8250_serial_out(struct uart_port *p, int offset, int value)
         if (offset == UART_LCR) {
                 int tries = 1000;
                 while (tries--) {
-                        if (value == p->serial_in(p, UART_LCR))
+                        unsigned int lcr = p->serial_in(p, UART_LCR);
+                        if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
                                 return;
                         dw8250_force_idle(p);
                         writeb(value, p->membase + (UART_LCR << p->regshift));
@@ -132,7 +133,8 @@ static void dw8250_serial_out32(struct uart_port *p, int offset, int value)
         if (offset == UART_LCR) {
                 int tries = 1000;
                 while (tries--) {
-                        if (value == p->serial_in(p, UART_LCR))
+                        unsigned int lcr = p->serial_in(p, UART_LCR);
+                        if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
                                 return;
                         dw8250_force_idle(p);
                         writel(value, p->membase + (UART_LCR << p->regshift));
@@ -455,6 +457,8 @@ MODULE_DEVICE_TABLE(of, dw8250_of_match);
 static const struct acpi_device_id dw8250_acpi_match[] = {
         { "INT33C4", 0 },
         { "INT33C5", 0 },
+        { "INT3434", 0 },
+        { "INT3435", 0 },
         { "80860F0A", 0 },
         { },
 };
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index f3b306efaa59..23329918f229 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -41,7 +41,7 @@ config SERIAL_8250_DEPRECATED_OPTIONS
           accept kernel parameters in both forms like 8250_core.nr_uarts=4 and
           8250.nr_uarts=4. We now renamed the module back to 8250, but if
           anybody noticed in 3.7 and changed their userspace we still have to
-          keep the 8350_core.* options around until they revert the changes
+          keep the 8250_core.* options around until they revert the changes
           they already did.
 
           If 8250 is built as a module, this adds 8250_core alias instead. 
diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
index 481b781b26e3..e9d420ff3931 100644
--- a/drivers/tty/serial/pmac_zilog.c
+++ b/drivers/tty/serial/pmac_zilog.c
@@ -2052,6 +2052,9 @@ static int __init pmz_console_init(void)
         /* Probe ports */
         pmz_probe();
 
+        if (pmz_ports_count == 0)
+                return -ENODEV;
+
         /* TODO: Autoprobe console based on OF */
         /* pmz_console.index = i; */
         register_console(&pmz_console);
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index e46e9f3f19b9..f619ad5b5eae 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -240,6 +240,7 @@ static irqreturn_t xuartps_isr(int irq, void *dev_id)
                                         continue;
                         }
 
+#ifdef SUPPORT_SYSRQ
                         /*
                          * uart_handle_sysrq_char() doesn't work if
                          * spinlocked, for some reason
@@ -253,6 +254,7 @@ static irqreturn_t xuartps_isr(int irq, void *dev_id)
                                 }
                                 spin_lock(&port->lock);
                         }
+#endif
 
                         port->icount.rx++;
 
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 3a1a01af9a80..c74a00ad7add 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2086,6 +2086,7 @@ retry_open:
                         filp->f_op = &tty_fops;
                 goto retry_open;
         }
+        clear_bit(TTY_HUPPED, &tty->flags);
         tty_unlock(tty);
 
 
diff --git a/drivers/tty/tty_ldsem.c b/drivers/tty/tty_ldsem.c
index 22fad8ad5ac2..d8a55e87877f 100644
--- a/drivers/tty/tty_ldsem.c
+++ b/drivers/tty/tty_ldsem.c
@@ -86,11 +86,21 @@ static inline long ldsem_atomic_update(long delta, struct ld_semaphore *sem)
         return atomic_long_add_return(delta, (atomic_long_t *)&sem->count);
 }
 
+/*
+ * ldsem_cmpxchg() updates @*old with the last-known sem->count value.
+ * Returns 1 if count was successfully changed; @*old will have @new value.
+ * Returns 0 if count was not changed; @*old will have most recent sem->count
+ */
 static inline int ldsem_cmpxchg(long *old, long new, struct ld_semaphore *sem)
 {
-        long tmp = *old;
-        *old = atomic_long_cmpxchg(&sem->count, *old, new);
-        return *old == tmp;
+        long tmp = atomic_long_cmpxchg(&sem->count, *old, new);
+        if (tmp == *old) {
+                *old = new;
+                return 1;
+        } else {
+                *old = tmp;
+                return 0;
+        }
 }
 
 /*