From 0943d8ead30e9474034cc5e92225ab0fd29fd0d4 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 26 May 2014 19:23:51 +0200 Subject: [PATCH] USB: cdc-acm: use tty-port dtr_rts Add dtr_rts tty-port operation which implements proper DTR/RTS handling (e.g. only lower DTR/RTS during shutdown if HUPCL is set). Note that modem-control locking still needs to be added throughout the driver. Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/cdc-acm.c | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 8f654ce52570..e934e19f49f5 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -504,6 +504,25 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp) return tty_port_open(&acm->port, tty, filp); } +static void acm_port_dtr_rts(struct tty_port *port, int raise) +{ + struct acm *acm = container_of(port, struct acm, port); + int val; + int res; + + if (raise) + val = ACM_CTRL_DTR | ACM_CTRL_RTS; + else + val = 0; + + /* FIXME: add missing ctrlout locking throughout driver */ + acm->ctrlout = val; + + res = acm_set_control(acm, val); + if (res && (acm->ctrl_caps & USB_CDC_CAP_LINE)) + dev_err(&acm->control->dev, "failed to set dtr/rts\n"); +} + static int acm_port_activate(struct tty_port *port, struct tty_struct *tty) { struct acm *acm = container_of(port, struct acm, port); @@ -535,11 +554,6 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty) goto error_submit_urb; } - acm->ctrlout = ACM_CTRL_DTR | ACM_CTRL_RTS; - retval = acm_set_control(acm, acm->ctrlout); - if (retval < 0 && (acm->ctrl_caps & USB_CDC_CAP_LINE)) - goto error_set_control; - /* * Unthrottle device in case the TTY was closed while throttled. */ @@ -561,9 +575,6 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty) error_submit_read_urbs: for (i = 0; i < acm->rx_buflimit; i++) usb_kill_urb(acm->read_urbs[i]); - acm->ctrlout = 0; - acm_set_control(acm, acm->ctrlout); -error_set_control: usb_kill_urb(acm->ctrlurb); error_submit_urb: usb_autopm_put_interface(acm->control); @@ -595,8 +606,6 @@ static void acm_port_shutdown(struct tty_port *port) dev_dbg(&acm->control->dev, "%s\n", __func__); - acm_set_control(acm, acm->ctrlout = 0); - /* * Need to grab write_lock to prevent race with resume, but no need to * hold it due to the tty-port initialised flag. @@ -992,6 +1001,7 @@ static void acm_tty_set_termios(struct tty_struct *tty, } static const struct tty_port_operations acm_port_ops = { + .dtr_rts = acm_port_dtr_rts, .shutdown = acm_port_shutdown, .activate = acm_port_activate, .destruct = acm_port_destruct, @@ -1429,8 +1439,6 @@ skip_countries: dev_info(&intf->dev, "ttyACM%d: USB ACM device\n", minor); - acm_set_control(acm, acm->ctrlout); - acm->line.dwDTERate = cpu_to_le32(9600); acm->line.bDataBits = 8; acm_set_line(acm, &acm->line); -- 2.39.2