sc16is7xx: remove useless "uart_handle_cts_change"

SC16is7xx has feature for auto hardware flow control using RTS/CTS,
so we don't need "uart_handle_cts_change" to invoke "start_tx/stop_tx"
for flow control.

In addition, for software CTS, interrupt "SC16IS7XX_IIR_CTSRTS_SRC"
just report the nCTS change of state from active(low) to inactive(high),
driver don't know when the state of nCTS change from incactive to active,
so can't resume the transmission when a peer device is again ready and
re-assert nRTS signal.

Signed-off-by: Wills Wang <wills.wang@live.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 025a4264430e80d280d2144828a51f5f79482a86..917504a60e98ce33a22b6e64eec52b92b8b0c102 100644 (file)
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -666,7 +666,7 @@ static void sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
        struct uart_port *port = &s->p[portno].port;
 
        do {
-               unsigned int iir, msr, rxlen;
+               unsigned int iir, rxlen;
 
                iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
                if (iir & SC16IS7XX_IIR_NO_INT_BIT)
@@ -683,12 +683,6 @@ static void sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
                        if (rxlen)
                                sc16is7xx_handle_rx(port, rxlen, iir);
                        break;
-
-               case SC16IS7XX_IIR_CTSRTS_SRC:
-                       msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG);
-                       uart_handle_cts_change(port,
-                                              !!(msr & SC16IS7XX_MSR_DCTS_BIT));
-                       break;
                case SC16IS7XX_IIR_THRI_SRC:
                        sc16is7xx_handle_tx(port);
                        break;
@@ -1014,9 +1008,8 @@ static int sc16is7xx_startup(struct uart_port *port)
                              SC16IS7XX_EFCR_TXDISABLE_BIT,
                              0);
 
-       /* Enable RX, TX, CTS change interrupts */
-       val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_THRI_BIT |
-             SC16IS7XX_IER_CTSI_BIT;
+       /* Enable RX, TX interrupts */
+       val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_THRI_BIT;
        sc16is7xx_port_write(port, SC16IS7XX_IER_REG, val);
 
        return 0;