serial: 8250_pci: report DCD and DSR signals as active for Bay Trail

Bay Trail UART port does not support DCD and DSR lines. The driver
shall report that these signals are permanently active. This patch
is for HSUART enumerated via PCI.

For ACPI, see commit dfd37668ea ("serial: 8250_dw: Fix get_mctrl
behaviour"). The commit also describes the possible issue if these
signals are enabled on a port without these pins.

Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Wan Ahmad Zainie 2016-04-06 12:06:52 +08:00 committed by Greg Kroah-Hartman
parent 144ef5c2df
commit c2684ed7d0

View file

@ -1416,6 +1416,17 @@ static bool byt_dma_filter(struct dma_chan *chan, void *param)
return true;
}
static unsigned int
byt_get_mctrl(struct uart_port *port)
{
unsigned int ret = serial8250_do_get_mctrl(port);
/* Force DCD and DSR signals to permanently be reported as active. */
ret |= TIOCM_CAR | TIOCM_DSR;
return ret;
}
static int
byt_serial_setup(struct serial_private *priv,
const struct pciserial_board *board,
@ -1480,6 +1491,7 @@ byt_serial_setup(struct serial_private *priv,
port->port.type = PORT_16550A;
port->port.flags = (port->port.flags | UPF_FIXED_PORT | UPF_FIXED_TYPE);
port->port.set_termios = byt_set_termios;
port->port.get_mctrl = byt_get_mctrl;
port->port.fifosize = 64;
port->tx_loadsz = 64;
port->dma = dma;