Merge tag 'tty-3.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial fixes from Greg KH:
 "Here are some small serial fixes that resolve some reported problems
  that started in 3.15 with some serial drivers.

  And there's a new dt binding for a serial driver, which was all that
  was needed for the renesas serial driver"

* tag 'tty-3.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: sh-sci: Add device tree support for r8a7{778,740,3a4} and sh73a0
  serial: imx: Fix build breakage
  serial: arc_uart: Use uart_circ_empty() for open-coded comparison
  serial: Test for no tx data on tx restart

8 files changed, 26 insertions, 4 deletions

diff --git a/Documentation/devicetree/bindings/serial/renesas,sci-serial.txt b/Documentation/devicetree/bindings/serial/renesas,sci-serial.txt
index 64fd7dec1bbc..b3556609a06f 100644
--- a/Documentation/devicetree/bindings/serial/renesas,sci-serial.txt
+++ b/Documentation/devicetree/bindings/serial/renesas,sci-serial.txt
@@ -4,6 +4,13 @@ Required properties:
 
   - compatible: Must contain one of the following:
 
+    - "renesas,scifa-sh73a0" for SH73A0 (SH-Mobile AG5) SCIFA compatible UART.
+    - "renesas,scifb-sh73a0" for SH73A0 (SH-Mobile AG5) SCIFB compatible UART.
+    - "renesas,scifa-r8a73a4" for R8A73A4 (R-Mobile APE6) SCIFA compatible UART.
+    - "renesas,scifb-r8a73a4" for R8A73A4 (R-Mobile APE6) SCIFB compatible UART.
+    - "renesas,scifa-r8a7740" for R8A7740 (R-Mobile A1) SCIFA compatible UART.
+    - "renesas,scifb-r8a7740" for R8A7740 (R-Mobile A1) SCIFB compatible UART.
+    - "renesas,scif-r8a7778" for R8A7778 (R-Car M1) SCIF compatible UART.
     - "renesas,scif-r8a7779" for R8A7779 (R-Car H1) SCIF compatible UART.
     - "renesas,scif-r8a7790" for R8A7790 (R-Car H2) SCIF compatible UART.
     - "renesas,scifa-r8a7790" for R8A7790 (R-Car H2) SCIFA compatible UART.
diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c
index c9f5c9dcc15c..008c223eaf26 100644
--- a/drivers/tty/serial/arc_uart.c
+++ b/drivers/tty/serial/arc_uart.c
@@ -177,7 +177,7 @@ static void arc_serial_tx_chars(struct arc_uart_port *uart)
                 uart->port.icount.tx++;
                 uart->port.x_char = 0;
                 sent = 1;
-        } else if (xmit->tail != xmit->head) {  /* TODO: uart_circ_empty */
+        } else if (!uart_circ_empty(xmit)) {
                 ch = xmit->buf[xmit->tail];
                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
                 uart->port.icount.tx++;
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index e2f93874989b..044e86d528ae 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -567,6 +567,9 @@ static void imx_start_tx(struct uart_port *port)
         struct imx_port *sport = (struct imx_port *)port;
         unsigned long temp;
 
+        if (uart_circ_empty(&port->state->xmit))
+                return;
+
         if (USE_IRDA(sport)) {
                 /* half duplex in IrDA mode; have to disable receive mode */
                 temp = readl(sport->port.membase + UCR4);
diff --git a/drivers/tty/serial/ip22zilog.c b/drivers/tty/serial/ip22zilog.c
index 1efd4c36ba0c..99b7b8697861 100644
--- a/drivers/tty/serial/ip22zilog.c
+++ b/drivers/tty/serial/ip22zilog.c
@@ -603,6 +603,8 @@ static void ip22zilog_start_tx(struct uart_port *port)
         } else {
                 struct circ_buf *xmit = &port->state->xmit;
 
+                if (uart_circ_empty(xmit))
+                        return;
                 writeb(xmit->buf[xmit->tail], &channel->data);
                 ZSDELAY();
                 ZS_WSYNC(channel);
diff --git a/drivers/tty/serial/m32r_sio.c b/drivers/tty/serial/m32r_sio.c
index 68f2c53e0b54..5702828fb62e 100644
--- a/drivers/tty/serial/m32r_sio.c
+++ b/drivers/tty/serial/m32r_sio.c
@@ -266,9 +266,11 @@ static void m32r_sio_start_tx(struct uart_port *port)
         if (!(up->ier & UART_IER_THRI)) {
                 up->ier |= UART_IER_THRI;
                 serial_out(up, UART_IER, up->ier);
-                serial_out(up, UART_TX, xmit->buf[xmit->tail]);
-                xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
-                up->port.icount.tx++;
+                if (!uart_circ_empty(xmit)) {
+                        serial_out(up, UART_TX, xmit->buf[xmit->tail]);
+                        xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+                        up->port.icount.tx++;
+                }
         }
         while((serial_in(up, UART_LSR) & UART_EMPTY) != UART_EMPTY);
 #else
diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
index 8193635103ee..f7ad5b903055 100644
--- a/drivers/tty/serial/pmac_zilog.c
+++ b/drivers/tty/serial/pmac_zilog.c
@@ -653,6 +653,8 @@ static void pmz_start_tx(struct uart_port *port)
         } else {
                 struct circ_buf *xmit = &port->state->xmit;
 
+                if (uart_circ_empty(xmit))
+                        goto out;
                 write_zsdata(uap, xmit->buf[xmit->tail]);
                 zssync(uap);
                 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
@@ -661,6 +663,7 @@ static void pmz_start_tx(struct uart_port *port)
                 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
                         uart_write_wakeup(&uap->port);
         }
+ out:
         pmz_debug("pmz: start_tx() done.\n");
 }
 
diff --git a/drivers/tty/serial/sunsab.c b/drivers/tty/serial/sunsab.c
index 80a58eca785b..2f57df9a71d9 100644
--- a/drivers/tty/serial/sunsab.c
+++ b/drivers/tty/serial/sunsab.c
@@ -427,6 +427,9 @@ static void sunsab_start_tx(struct uart_port *port)
         struct circ_buf *xmit = &up->port.state->xmit;
         int i;
 
+        if (uart_circ_empty(xmit))
+                return;
+
         up->interrupt_mask1 &= ~(SAB82532_IMR1_ALLS|SAB82532_IMR1_XPR);
         writeb(up->interrupt_mask1, &up->regs->w.imr1);
         
diff --git a/drivers/tty/serial/sunzilog.c b/drivers/tty/serial/sunzilog.c
index a85db8b87156..02df3940b95e 100644
--- a/drivers/tty/serial/sunzilog.c
+++ b/drivers/tty/serial/sunzilog.c
@@ -703,6 +703,8 @@ static void sunzilog_start_tx(struct uart_port *port)
         } else {
                 struct circ_buf *xmit = &port->state->xmit;
 
+                if (uart_circ_empty(xmit))
+                        return;
                 writeb(xmit->buf[xmit->tail], &channel->data);
                 ZSDELAY();
                 ZS_WSYNC(channel);