redonkable/alistair23-linux
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sc16is7xx: remove useless "uart_handle_cts_change"

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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>
This commit is contained in:
Wills Wang 2016-03-05 22:09:05 +08:00 committed by Greg Kroah-Hartman
parent 03e970bba4
commit e69ef01ff0
1 changed files with 3 additions and 10 deletions
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13
drivers/tty/serial/sc16is7xx.c
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@ -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;