On Mon, 8 Mar 2010, Jason Wessel wrote: > Commit e1108a63e10d344284011cccc06328b2cd3e5da3 ("usb_serial: Use the > shutdown() operation") breaks the ability to use a usb console > starting in 2.6.32. This was observed when using > console=ttyUSB0,115200 as a boot argument with an FTDI device. The > error is: > > ftdi_sio ttyUSB0: ftdi_submit_read_urb - failed submitting read urb, error -22 > > The handling of the ASYNCB_INITIALIZED changed in 2.6.32 such that in > tty_port_shutdown() it always clears the flag if it is set. As a work > around the usb console must reset this flag, in order for the hw to > stay open. > > CC: Greg Kroah-Hartman <gregkh@xxxxxxx> > CC: Alan Cox <alan@xxxxxxxxxxxxxxx> > CC: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > CC: Oliver Neukum <oliver@xxxxxxxxxx> > CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > CC: linux-usb@xxxxxxxxxxxxxxx > CC: linux-kernel@xxxxxxxxxxxxxxx > Signed-off-by: Jason Wessel <jason.wessel@xxxxxxxxxxxxx> > > --- > drivers/usb/serial/usb-serial.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > --- a/drivers/usb/serial/usb-serial.c > +++ b/drivers/usb/serial/usb-serial.c > @@ -287,10 +287,13 @@ static void serial_down(struct tty_port > struct usb_serial_driver *drv = port->serial->type; > /* > * The console is magical. Do not hang up the console hardware > - * or there will be tears. > + * or there will be tears. If this is a console the initialized > + * flag is reset. > */ > - if (port->console) > + if (port->console) { > + set_bit(ASYNCB_INITIALIZED, &port->port.flags); > return; > + } > if (drv->close) > drv->close(port); > } This is a little unfortunate. It would be better to prevent tty_port_shutdown() from clearing ASYNCB_INITIALIZED in the first place. The problem is that the tty core doesn't know when the port is being used as a console. There ought to be a way to tell it. Alan Stern -- 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