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USB: cdc-acm: use tty-port dtr_rts

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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 <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johan Hovold 2014-05-26 19:23:51 +02:00 committed by Greg Kroah-Hartman
parent 308fee18e0
commit 0943d8ead3
1 changed files with 20 additions and 12 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

32
drivers/usb/class/cdc-acm.c
View file

@ -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 @@ static int acm_probe(struct usb_interface *intf,
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);