diff options
| author | Jiri Slaby <jslaby@suse.cz> | 2011-08-17 13:48:15 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-08-23 10:10:38 -0700 |
| commit | 0055197e984e5fbe6f48f37fc50dd30254915493 (patch) | |
| tree | df7de31cd63bc231a37fd6833ba53e40140ceff5 | |
| parent | 24d406a6bf736f7aebdc8fa0f0ec86e0890c6d24 (diff) | |
| download | xen-0055197e984e5fbe6f48f37fc50dd30254915493.tar.gz | |
TTY: serial, document ignoring of uart->ops->startup error
When a user has SYS_ADMIN capabilities and uart->ops->startup returns
an error in uart_startup, we silently drop the error. We then return 0
and behave as if it didn't fail. (Not quite, since we set TTY_IO_ERROR
bit and leave ASYNC_INITIALIZED bit cleared.)
This all is to allow setserial to work with improperly configured or
unconfigured ports. User can thus set port properties and reconfigure
properly.
This patch only documents this behavior.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Russel King <linux@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/tty/serial/serial_core.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index db7912cb7ae04..a3efbea5dbba6 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -200,6 +200,11 @@ static int uart_startup(struct tty_struct *tty, struct uart_state *state, int in clear_bit(TTY_IO_ERROR, &tty->flags); } + /* + * This is to allow setserial on this port. People may want to set + * port/irq/type and then reconfigure the port properly if it failed + * now. + */ if (retval && capable(CAP_SYS_ADMIN)) retval = 0; |