On 03/10/2014 09:06 PM, Peter Hurley wrote:
[ +cc Alan ]
On 02/28/2014 08:21 AM, Geert Uytterhoeven wrote:
From: Geert Uytterhoeven <geert+renesas@xxxxxxxxxxxxxx>
If the serial port being removed is used as a console, it must also be
unregistered from the console subsystem using unregister_console().
uart_ops.release_port() will release resources (e.g. iounmap() the serial
port registers), causing a crash on subsequent kernel output if the console
is still registered.
This brings up an interesting point: where are the serial_core drivers
indicating to the tty core that the port is bound to a console?
IOW, I cannot find a single 'port->console = 1' anywhere in the serial tree.
Answering half my own question: I see that serial_core doesn't use
tty_port_shutdown() but rather has it's own uart_shutdown() equivalent, and
thus doesn't use 'port->console'.
Ok.
But I still don't see what prevents a uart_port_shutdown() on a running
serial console.
Regards,
Peter Hurley
It would be bad if the uart port disappears while a console is running
on it...
Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxxxxxxx>
---
drivers/tty/serial/serial_core.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index ece2049bd270..8ece7f14d89d 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2677,6 +2677,12 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
tty_vhangup(port->tty);
/*
+ * If the port is used as a console, unregister it
+ */
+ if (uart_console(uport))
+ unregister_console(uport->cons);
+
+ /*
* Free the port IO and memory resources, if any.
*/
if (uport->type != PORT_UNKNOWN)
--
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