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 <[email protected]> --- 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 e78fa99..6dcf449 100644 --- 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; @@ -1020,9 +1014,8 @@ 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
