serial: 8250: Refactor serial8250_rx_chars() inner loop

Factor the read/process one char inner loop to a separate helper
function serial8250_read_char(). No functional change.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 8d262bce97e410a58ed7fc3ba703bf8ba15cfb6d..7580d713cde5b0b7f24c5fc3d0aa0a0600cdca58 100644 (file)
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1412,6 +1412,67 @@ static void serial8250_enable_ms(struct uart_port *port)
        serial8250_rpm_put(up);
 }
 
+static void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr)
+{
+       struct uart_port *port = &up->port;
+       unsigned char ch;
+       char flag = TTY_NORMAL;
+
+       if (likely(lsr & UART_LSR_DR))
+               ch = serial_in(up, UART_RX);
+       else
+               /*
+                * Intel 82571 has a Serial Over Lan device that will
+                * set UART_LSR_BI without setting UART_LSR_DR when
+                * it receives a break. To avoid reading from the
+                * receive buffer without UART_LSR_DR bit set, we
+                * just force the read character to be 0
+                */
+               ch = 0;
+
+       port->icount.rx++;
+
+       lsr |= up->lsr_saved_flags;
+       up->lsr_saved_flags = 0;
+
+       if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
+               if (lsr & UART_LSR_BI) {
+                       lsr &= ~(UART_LSR_FE | UART_LSR_PE);
+                       port->icount.brk++;
+                       /*
+                        * We do the SysRQ and SAK checking
+                        * here because otherwise the break
+                        * may get masked by ignore_status_mask
+                        * or read_status_mask.
+                        */
+                       if (uart_handle_break(port))
+                               return;
+               } else if (lsr & UART_LSR_PE)
+                       port->icount.parity++;
+               else if (lsr & UART_LSR_FE)
+                       port->icount.frame++;
+               if (lsr & UART_LSR_OE)
+                       port->icount.overrun++;
+
+               /*
+                * Mask off conditions which should be ignored.
+                */
+               lsr &= port->read_status_mask;
+
+               if (lsr & UART_LSR_BI) {
+                       DEBUG_INTR("handling break....");
+                       flag = TTY_BREAK;
+               } else if (lsr & UART_LSR_PE)
+                       flag = TTY_PARITY;
+               else if (lsr & UART_LSR_FE)
+                       flag = TTY_FRAME;
+       }
+       if (uart_handle_sysrq_char(port, ch))
+               return;
+
+       uart_insert_char(port, lsr, UART_LSR_OE, ch, flag);
+}
+
 /*
  * serial8250_rx_chars: processes according to the passed in LSR
  * value, and returns the remaining LSR bits not handled
@@ -1421,67 +1482,10 @@ unsigned char
 serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr)
 {
        struct uart_port *port = &up->port;
-       unsigned char ch;
        int max_count = 256;
-       char flag;
 
        do {
-               if (likely(lsr & UART_LSR_DR))
-                       ch = serial_in(up, UART_RX);
-               else
-                       /*
-                        * Intel 82571 has a Serial Over Lan device that will
-                        * set UART_LSR_BI without setting UART_LSR_DR when
-                        * it receives a break. To avoid reading from the
-                        * receive buffer without UART_LSR_DR bit set, we
-                        * just force the read character to be 0
-                        */
-                       ch = 0;
-
-               flag = TTY_NORMAL;
-               port->icount.rx++;
-
-               lsr |= up->lsr_saved_flags;
-               up->lsr_saved_flags = 0;
-
-               if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) {
-                       if (lsr & UART_LSR_BI) {
-                               lsr &= ~(UART_LSR_FE | UART_LSR_PE);
-                               port->icount.brk++;
-                               /*
-                                * We do the SysRQ and SAK checking
-                                * here because otherwise the break
-                                * may get masked by ignore_status_mask
-                                * or read_status_mask.
-                                */
-                               if (uart_handle_break(port))
-                                       goto ignore_char;
-                       } else if (lsr & UART_LSR_PE)
-                               port->icount.parity++;
-                       else if (lsr & UART_LSR_FE)
-                               port->icount.frame++;
-                       if (lsr & UART_LSR_OE)
-                               port->icount.overrun++;
-
-                       /*
-                        * Mask off conditions which should be ignored.
-                        */
-                       lsr &= port->read_status_mask;
-
-                       if (lsr & UART_LSR_BI) {
-                               DEBUG_INTR("handling break....");
-                               flag = TTY_BREAK;
-                       } else if (lsr & UART_LSR_PE)
-                               flag = TTY_PARITY;
-                       else if (lsr & UART_LSR_FE)
-                               flag = TTY_FRAME;
-               }
-               if (uart_handle_sysrq_char(port, ch))
-                       goto ignore_char;
-
-               uart_insert_char(port, lsr, UART_LSR_OE, ch, flag);
-
-ignore_char:
+               serial8250_read_char(up, lsr);
                lsr = serial_in(up, UART_LSR);
        } while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (--max_count > 0));
        spin_unlock(&port->lock);