tty_port: If we are opened non blocking we still need to raise the carrier
authorAlan Cox <alan@linux.intel.com>
Wed, 28 Oct 2009 20:12:32 +0000 (21:12 +0100)
committerGreg Kroah-Hartman <gregkh@suse.de>
Wed, 18 Nov 2009 00:42:28 +0000 (16:42 -0800)
commit4175f3e31cc7157669aa66d46dc79de6ae0126ce
treede3c0ff054f3c403c5354b23c52f3e8e5e7c5510
parentac50e950784cae1c26ad9e09ebd8f8c706131eb3
tty_port: If we are opened non blocking we still need to raise the carrier

Original discussion:
http://thread.gmane.org/gmane.linux.usb.general/23217/focus=23248
or
http://marc.info/?l=linux-usb&m=125553790714133&w=2

The tty_port code inherited a bug common to various drivers it was based
upon. If the tty is opened O_NONBLOCK we do not wait for the carrier to be
raised but we must still raise our modem lines if appropriate.

(There is a second question here about whether we should do so if CLOCAL is
 set but that can wait)

Signed-off-by: Alan Cox <alan@linux.intel.com>
Reported-by: Karl Hiramoto <karl@hiramoto.org>
Tested-by:  Karl Hiramoto <karl@hiramoto.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/char/tty_port.c