The commit 335f8514f200e63d689113d29cb7253a5c282967 introduced a
regression which stopped usb consoles from working correctly as a
kernel boot console as well as interactive login device.

The addition of the serial_close() which in turn calls
tty_port_close_start() will change the reference count of port.count
and warn about it.  The usb console code had previously incremented
the port.count to indicate it was making use of the device as a
console and the forced change causes a double open on the usb device
which leads to a non obvious kernel oops later on when the tty is
freed.

To fix the problem instead make use of port->console to track if the
port is in fact an active console port to avoid double initialization
of the usb serial device.  The port.count is incremented and
decremented only with in the scope of usb_console_setup() for the
purpose of the low level driver initialization.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

This allows us to clean stuff up, but is probably also going to cause
some app breakage with buggy apps as we now implement proper POSIX behaviour
for USB ports matching all the other ports. This does also mean other apps
that break on USB will now work properly.

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Add device funtion for usb serial console, so we can open /dev/console
when we use a usb serial device as console.

(Typecast removed as noted by Sergei Shtylyov)

Signed-off-by: Kevin Hao <kexin.hao@windriver.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We alloc a fake tty in usb serial console setup function. we should
init the tty's kref otherwise we will face WARN_ON after following
invoke of tty_port_tty_set --> tty_kref_get.

Signed-off-by: Kevin Hao <kexin.hao@windriver.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use kref in the USB serial drivers so that we don't free tty structures
from under the URB receive handlers as has historically been the case if
you were unlucky. This also gives us a framework for general tty drivers to
use tty_port objects and refcount.

Contains two err->dev_err changes merged together to fix clashes in the
-next tree.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The hw interface drivers for the usb serial devices deference the tty
structure to set up the parameters for the initial console.  The tty
structure should be passed as a parameter to the set_termios() call.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Setting CFLAG bits is all well and good but you must sort out ispeed and
ospeed properly.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Code tidy

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

USB serial likes to use port->tty back pointers for the real work it does and
to do so without any actual locking. Unfortunately when you consider hangup
events, hangup/parallel reopen or even worse hangup followed by parallel close
events the tty->port and port->tty pointers are not guaranteed to be the same
as port->tty is the active tty while tty->port is the port the tty may or
may not still be attached to.

So rework the entire API to pass the tty struct. For console cases we need
to pass both for now. This shows up multiple drivers that immediately crash
with USB console some of which have been fixed in the process.

Longer term we need a proper tty as console abstraction

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>