On Tue, 13 Oct 2009 22:41:59 +0200
Karl Hiramoto <karl@xxxxxxxxxxxx> wrote:
> This reverts 9a68e39d4a701fb3be03cae9b462408664ebd205
> Commit 9a68e39d4a701fb3be03cae9b462408664ebd205 breaks my hardware.
> After 9a68e39d4a opening the port in minicom or cutecom would produce no data flow.
> Kernels 2.6.15(or maybee earlier) through 2.6.30 worked fine up until 9a68e39d4a.
>
> Signed-off-by: Karl Hiramoto <karl@xxxxxxxxxxxx>
> Cc: stable <stable@xxxxxxxxxx>
>
> ---
> drivers/usb/serial/cp210x.c | 5 +++++
> 1 files changed, 5 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
> index 698252a..26a46e2 100644
> --- a/drivers/usb/serial/cp210x.c
> +++ b/drivers/usb/serial/cp210x.c
> @@ -398,6 +398,11 @@ static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
>
> /* Configure the termios structure */
> cp210x_get_termios(tty, port);
> +
> + /* Set the DTR and RTS pins low */
> + cp210x_tiocmset_port(tty ? (struct usb_serial_port *) tty->driver_data
> + : port, NULL, TIOCM_DTR | TIOCM_RTS, 0);
> +
This is fallout from actually making stuff standards compliant. The
DTR|RTS lines should get raised at the right moment but cp210x doesn't
yet have the needed code to do it when CLOCAL is clear. I think it didn't
show up in testing because if set_termios() is called it gets corrected
then.
Please try the following
cp210x: Fix carrier handling
From: Alan Cox <alan@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx>
---
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 698252a..bd254ec 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;
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
