From 4175f3e31cc7157669aa66d46dc79de6ae0126ce Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Wed, 28 Oct 2009 21:12:32 +0100 Subject: tty_port: If we are opened non blocking we still need to raise the carrier Original discussion: http://thread.gmane.org/gmane.linux.usb.general/23217/focus=23248 or http://marc.info/?l=linux-usb&m=125553790714133&w=2 The tty_port code inherited a bug common to various drivers it was based upon. If the tty is opened O_NONBLOCK we do not wait for the carrier to be raised but we must still raise our modem lines if appropriate. (There is a second question here about whether we should do so if CLOCAL is set but that can wait) Signed-off-by: Alan Cox Reported-by: Karl Hiramoto Tested-by: Karl Hiramoto Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/char/tty_port.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers') diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c index a4bbb28f10be..2e8552dc5eda 100644 --- a/drivers/char/tty_port.c +++ b/drivers/char/tty_port.c @@ -221,6 +221,9 @@ int tty_port_block_til_ready(struct tty_port *port, the port has just hung up or is in another error state */ if ((filp->f_flags & O_NONBLOCK) || (tty->flags & (1 << TTY_IO_ERROR))) { + /* Indicate we are open */ + if (tty->termios->c_cflag & CBAUD) + tty_port_raise_dtr_rts(port); port->flags |= ASYNC_NORMAL_ACTIVE; return 0; } -- cgit v1.2.2 From d94c7bd4c1361cab58a21d530078c5673863dcc2 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Wed, 28 Oct 2009 21:12:33 +0100 Subject: tty: cp210x: Fix carrier handling Original discussion: http://thread.gmane.org/gmane.linux.usb.general/23217/focus=23248 or http://marc.info/?l=linux-usb&m=125553790714133&w=2 9a68e39d4a701fb3be03cae9b462408664ebd205 broke carrier handling so that a cp210x setup which needed the carrier lines set up (non CLOCAL) which did not make a call which set the termios bits left the lines down even if CLOCAL was not asserted. Fix this not by reverting but by adding the proper dtr_rts and carrier_raised methods. This both sets the modem lines properly and also implements the correct blocking semantics for the port as required by POSIX. Signed-off-by: Alan Cox Reported-by: Karl Hiramoto Tested-by: Karl Hiramoto Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/cp210x.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'drivers') diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c index 698252a4dc5d..bd254ec97d14 100644 --- a/drivers/usb/serial/cp210x.c +++ b/drivers/usb/serial/cp210x.c @@ -50,6 +50,8 @@ static int cp210x_tiocmset_port(struct usb_serial_port *port, struct file *, static void cp210x_break_ctl(struct tty_struct *, int); static int cp210x_startup(struct usb_serial *); static void cp210x_disconnect(struct usb_serial *); +static void cp210x_dtr_rts(struct usb_serial_port *p, int on); +static int cp210x_carrier_raised(struct usb_serial_port *p); static int debug; @@ -143,6 +145,8 @@ static struct usb_serial_driver cp210x_device = { .tiocmset = cp210x_tiocmset, .attach = cp210x_startup, .disconnect = cp210x_disconnect, + .dtr_rts = cp210x_dtr_rts, + .carrier_raised = cp210x_carrier_raised }; /* Config request types */ @@ -746,6 +750,14 @@ static int cp210x_tiocmset_port(struct usb_serial_port *port, struct file *file, return cp210x_set_config(port, CP210X_SET_MHS, &control, 2); } +static void cp210x_dtr_rts(struct usb_serial_port *p, int on) +{ + if (on) + cp210x_tiocmset_port(p, NULL, TIOCM_DTR|TIOCM_RTS, 0); + else + cp210x_tiocmset_port(p, NULL, 0, TIOCM_DTR|TIOCM_RTS); +} + static int cp210x_tiocmget (struct tty_struct *tty, struct file *file) { struct usb_serial_port *port = tty->driver_data; @@ -768,6 +780,15 @@ static int cp210x_tiocmget (struct tty_struct *tty, struct file *file) return result; } +static int cp210x_carrier_raised(struct usb_serial_port *p) +{ + unsigned int control; + cp210x_get_config(p, CP210X_GET_MDMSTS, &control, 1); + if (control & CONTROL_DCD) + return 1; + return 0; +} + static void cp210x_break_ctl (struct tty_struct *tty, int break_state) { struct usb_serial_port *port = tty->driver_data; -- cgit v1.2.2