diff options
| author | Alan Cox <alan@linux.intel.com> | 2009-10-28 21:12:33 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-11-17 16:42:43 -0800 |
| commit | d94c7bd4c1361cab58a21d530078c5673863dcc2 (patch) | |
| tree | e62139e4d349a68dd698070af7619a9ce5122386 /drivers/usb/serial | |
| parent | 4175f3e31cc7157669aa66d46dc79de6ae0126ce (diff) | |
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 <alan@linux.intel.com>
Reported-by: Karl Hiramoto <karl@hiramoto.org>
Tested-by: Karl Hiramoto <karl@hiramoto.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/serial')
| -rw-r--r-- | drivers/usb/serial/cp210x.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c index 698252a4dc5..bd254ec97d1 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; |