From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756100Ab0JKT4e (ORCPT ); Mon, 11 Oct 2010 15:56:34 -0400 Received: from terminus.zytor.com ([198.137.202.10]:52287 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755674Ab0JKT4d (ORCPT ); Mon, 11 Oct 2010 15:56:33 -0400 Message-ID: <4CB36BDF.5040200@zytor.com> Date: Mon, 11 Oct 2010 12:56:15 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.9) Gecko/20100921 Fedora/3.1.4-1.fc13 Thunderbird/3.1.4 MIME-Version: 1.0 To: Yinghai Lu CC: Ingo Molnar , Thomas Gleixner , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] x86, setup: Check early serial console per string instead of one char References: <4CB34E82.8030802@kernel.org> <4CB3552C.5050808@zytor.com> <4CB369E5.6040600@kernel.org> In-Reply-To: <4CB369E5.6040600@kernel.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/11/2010 12:47 PM, Yinghai Lu wrote: >> >> This seems to add a bunch of code for zero benefit. Testing a global >> variable is zero cost compared to either a BIOS call or poking a serial >> port. > > some server have bios serial console redirection support, and bios int call could send char to screen and serial port. > > in that case, take out serial_putchar from putchar could produce more readable print out from serial console > That doesn't appear to have anything to do with this code change. What you're saying is that "if BIOS does serial console redirection, we shouldn't output to both the serial console and the BIOS console", which is of course a truism, but that doesn't justify in any way this particular code reconfiguration. -hpa