From: Jiri Slaby <jslaby@xxxxxxx> 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@xxxxxxx> Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> Cc: Russel King <linux@xxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx> --- 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 db7912c..a3efbea 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; -- 1.7.6.1 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
