Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932621AbVIMMCg (ORCPT ); Tue, 13 Sep 2005 08:02:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932622AbVIMMCg (ORCPT ); Tue, 13 Sep 2005 08:02:36 -0400 Received: from caramon.arm.linux.org.uk ([212.18.232.186]:32531 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S932621AbVIMMCf (ORCPT ); Tue, 13 Sep 2005 08:02:35 -0400 Date: Tue, 13 Sep 2005 13:02:29 +0100 From: Russell King To: Hironobu Ishii , Taku Izumi , akpm@osdl.org, linux-kernel@vger.kernel.org Subject: Re: performance-improvement-of-serial-console-via-virtual.patch added to -mm tree Message-ID: <20050913130229.B14342@flint.arm.linux.org.uk> Mail-Followup-To: Hironobu Ishii , Taku Izumi , akpm@osdl.org, linux-kernel@vger.kernel.org References: <200509072146.j87LkNv8004076@shell0.pdx.osdl.net> <20050907224911.H19199@flint.arm.linux.org.uk> <4394.10.124.102.246.1126165652.squirrel@dominion> <20050913091740.A8256@flint.arm.linux.org.uk> <00b601c5b858$8a8c4ad0$dba0220a@CARREN> <20050913125326.A14342@flint.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <20050913125326.A14342@flint.arm.linux.org.uk>; from rmk+lkml@arm.linux.org.uk on Tue, Sep 13, 2005 at 12:53:26PM +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1360 Lines: 30 On Tue, Sep 13, 2005 at 12:53:26PM +0100, Russell King wrote: > The only things which the console code can rely on being initialised > is the port address description (iobase / membase / iotype / regshift), > the flow control (UPF_CONS_FLOW) in flags, and in the case of Xscale > systems, the capabilities. Everything else will be in an indeterminent > state as far as the serial console code is concerned, and therefore can > not be relied upon. Additionally, once all architectures convert to initialising their serial ports via platform devices (which means include/asm-*/serial.h becomes essentially empty) and we eliminate serial8250_console_init(), the 8250 console code can start assuming that more of the uart_port structure will be initialised. At that point, we can start to think about using FIFOs for the console. However, this is an exercise for architecture maintainers to do who in theory know the requirements for their platforms. So far I've seen little progress on this though. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/