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.
---
drivers/tty/serial/sc16is7xx.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 9d18c24..d19a7ba 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -653,7 +653,7 @@ 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)
@@ -670,12 +670,6 @@ 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;
@@ -993,9 +987,8 @@ 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;
--
1.9.1
--
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