tree df7de31cd63bc231a37fd6833ba53e40140ceff5
parent 24d406a6bf736f7aebdc8fa0f0ec86e0890c6d24
author Jiri Slaby <jslaby@suse.cz> 1313581695 +0200
committer Greg Kroah-Hartman <gregkh@suse.de> 1314119438 -0700

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>