From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [patch 2/2] 8250_pnp: register x86 COM ports at the conventional ttyS names Date: Wed, 16 Jan 2008 14:49:44 -0500 Message-ID: <478E5FD8.5060906@zytor.com> References: <20080116170541.511233227@ldl.fc.hp.com> <20080116170914.959390017@ldl.fc.hp.com> <478E5095.2020803@zytor.com> <200801161247.34821.bjorn.helgaas@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from terminus.zytor.com ([198.137.202.10]:40295 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752708AbYAPT7N (ORCPT ); Wed, 16 Jan 2008 14:59:13 -0500 In-Reply-To: <200801161247.34821.bjorn.helgaas@hp.com> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Bjorn Helgaas Cc: Alan Cox , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, Russell King , Jeff Garzik , Andrew Morton Bjorn Helgaas wrote: >>> + >> Arguably, the right thing is to use the addresses present in the array >> at address 0x400. In particular, COM3 and COM4 aren't always at those >> addresses. > > Wow. I bow before your storehouse of x86 arcana :-) > > I guess you're referring to the "BIOS data area," which I'd never > heard of before (but fortunately, Google knows). > > What would you think about doing this only for COM1 and COM2? The > only real value for doing this in the first place is so "console=ttyS0" > always goes to COM1, even if we don't have SERIAL_PORT_DFNS. User- > space ought to use some sort of udev magic if it cares about persistent > naming. > Well, there are four ports that the BIOS have slots for, and if so, we probably should use them. -hpa