Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933192Ab1EROBW (ORCPT ); Wed, 18 May 2011 10:01:22 -0400 Received: from smtp-out.google.com ([74.125.121.67]:4503 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932843Ab1EROBV convert rfc822-to-8bit (ORCPT ); Wed, 18 May 2011 10:01:21 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type:content-transfer-encoding; b=jBJCiMlaQQIJYWw1GV1YyK7gTo+xhITk/6r54gjBMI3i3kYkA6xJF02LYUpUl+iHtn 4dzs0GzSyZS/fiX8ZVdg== MIME-Version: 1.0 In-Reply-To: <334319B2EBE0B144BAE1402B79D82DC5CE13B05A@srvpegasus> References: <334319B2EBE0B144BAE1402B79D82DC5CE13B056@srvpegasus> <334319B2EBE0B144BAE1402B79D82DC5CE13B05A@srvpegasus> From: Bjorn Helgaas Date: Wed, 18 May 2011 07:56:04 -0600 Message-ID: Subject: Re: Kernel > 2.6.30: PCI issue causes Kernel freeze at booting To: "Hornung, Michael" Cc: "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1270 Lines: 27 On Wed, May 18, 2011 at 1:44 AM, Hornung, Michael wrote: >>> There is an UART (FPGA IP Core) in that system located at address 1900h using interrupt 3. In order to get Kernel messages at boot time, >>> I changed file arch/x86/include/asm/serial.h as follows: >>> >>> - ? ? ? ?{ 0, BASE_BAUD, 0x3F8, 4, STD_COM_FLAGS }, ? ? ?/* ttyS0 */ ? ? \ >>> + ? ? ? ?{ 0, BASE_BAUD, 0x1900, 3, STD_COM_FLAGS }, ? ? /* ttyS0 */ ? ?\ >>> >>> that is the only change I made to the kernel sources. > >> Is this UART connected via PCI? ?I don't think so, because I don't see >> any I/O BARs that include 0x1900. > > The UART is connected via LPC bus. Makes sense; that's a common way for attaching UARTs, and they are normally described via ACPI. When you do that, I think it will show up as ttyS4 (be sure you build with CONFIG_SERIAL_8250_PNP=y), so you'll have to use "console=ttyS4" when you boot. ttyS0-ttyS3 are taken by the hard-coded ports in serial.h, even though they may not exist on your platform. Bjorn -- 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/