tree 9fac95e32736d6a172db90ccc376043af9ef039c
parent 469d6d0631386e6865a30c9ded87a5cc0fdf8e2e
author Rob Herring <rob.herring@calxeda.com> 1380074758 -0500
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1380157856 -0700

TTY: hvc_dcc: probe for a JTAG connection before registering

Enabling the ARM DCC console and using without a JTAG connection will
simply hang the system. Since distros like to turn on all options, this
is a reoccurring problem to debug. We can do better by checking if
anything is attached and handling characters. There is no way to probe
this, so send a newline and check that it is handled.

Cc: Paolo Pisati <paolo.pisati@canonical.com>
Cc: Tim Gardner <tim.gardner@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>