After commit "TTY: move tty buffers to tty_port", the tty buffers are
not freed in some drivers. This is because tty_port_destructor is not
called whenever a tty_port is freed. This was an assumption I counted
with but was unfortunately untrue. So fix the drivers to fulfil this
assumption.
To be sure, the TTY buffers (and later some stuff) are gone along with
the tty_port, we have to call tty_port_destroy at tear-down places.
This is mostly where the structure containing a tty_port is freed.
This patch does exactly that -- put tty_port_destroy at those places.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This special driver makes it possible to temporary use NMI debugger port
as a normal console by issuing 'nmi_console' command (assuming that the
port is attached to KGDB).
Unlike KDB's disable_nmi command, with this driver you are always able
to go back to the debugger using KGDB escape sequence ($3#33). This is
because this console driver processes the input in NMI context, and thus
is able to intercept the magic sequence.
Note that since the console interprets input and uses polling
communication methods, for things like PPP it is still better to fully
detach debugger port from the KGDB NMI (i.e. disable_nmi), and use raw
console.
Usually, to enter the debugger one have to type the magic sequence, so
initially the kernel will print the following prompt on the NMI debugger
console:
Type $3#33 to enter the debugger>
For convenience, there is a kgdb_fiq.knock kernel command line option,
when set to 0, this turns the special command to just a return key
press, so the kernel will be printing this:
Hit <return> to enter the debugger>
This is more convenient for long debugging sessions, although it makes
nmi_console feature somewhat useless.
And for the cases when NMI connected to a dedicated button, the knocking
can be disabled altogether by setting kgdb_fiq.knock to -1.
Suggested-by: Colin Cross <ccross@android.com>
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Alan Cox <alan@linux.intel.com>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
