From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752737Ab0KRLYs (ORCPT ); Thu, 18 Nov 2010 06:24:48 -0500 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:40727 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751016Ab0KRLYr (ORCPT ); Thu, 18 Nov 2010 06:24:47 -0500 Date: Thu, 18 Nov 2010 11:23:35 +0000 From: Alan Cox To: "Dr. Werner Fink" Cc: Greg KH , Lennart Poettering , Kay Sievers , Valdis.Kletnieks@vt.edu, linux-kernel , Randy Dunlap , Jiri Slaby Subject: Re: tty: add 'active' sysfs attribute to tty0 and console device Message-ID: <20101118112335.434de53a@lxorguk.ukuu.org.uk> In-Reply-To: <20101118110020.GA13871@boole.suse.de> References: <20101116195538.7fa66b97@lxorguk.ukuu.org.uk> <20101116213622.GA17824@tango.0pointer.de> <20101116225619.5fa7ef8b@lxorguk.ukuu.org.uk> <20101116231023.GB27594@tango.0pointer.de> <25482.1290031268@localhost> <20101117235647.00766e32@lxorguk.ukuu.org.uk> <20101118012734.GA8558@kroah.com> <20101118014848.GA7873@tango.0pointer.de> <20101118015310.GA30480@kroah.com> <20101118110020.GA13871@boole.suse.de> X-Mailer: Claws Mail 3.7.6 (GTK+ 2.18.9; x86_64-redhat-linux-gnu) Face: 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 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > is the most pressing case e.g. on s390 or zSeries) and this without > forcing (and maybe stealing) the controlling tty on the system console > to be able to detect the primary tty/console. What do you mean by console in this context The console in printk context and the "console" in "active vt window" are unrelated concepts with the same name, so its a bit confusing to follow here. > facilities (having device, read, write, and unblank) are also shown > in the new file /sys/class/tty/console/active ... but maybe Randy > could says a few words for what this is usable. The system console does not even need to be a tty device, and on many embedded devices is not (it may for example by a RAM buffer not wiped over reboots or it may be jtag or MIPI trace ports. "tty0" is *currently* a shorthand for "the VT the keyboard/display are showing". That's a shorthand that in itself will make no sense in future. Alan