From: Alan Cox Date: Wed, 28 Oct 2009 20:12:33 +0000 (+0100) Subject: tty: cp210x: Fix carrier handling X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=d94c7bd4c1361cab58a21d530078c5673863dcc2;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git 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 --- 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;