From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755907AbaHVKDi (ORCPT ); Fri, 22 Aug 2014 06:03:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:3841 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751556AbaHVKDg (ORCPT ); Fri, 22 Aug 2014 06:03:36 -0400 Date: Fri, 22 Aug 2014 18:04:56 +0800 From: Dave Young To: "Zheng, Lv" Cc: Matt Fleming , "Fleming, Matt" , "linux-efi@vger.kernel.org" , "linux-acpi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "devel@acpica.org" , "lenb@kernel.org" , "Wysocki, Rafael J" , "Moore, Robert" , "Lv Zheng (zetalog@gmail.com)" Subject: Re: kernel boot fail with efi earlyprintk (bisected) Message-ID: <20140822100456.GB1877@darkstar.nay.redhat.com> References: <20140819081658.GA1795@darkstar.nay.redhat.com> <20140821205224.GJ29733@console-pimps.org> <1AE640813FDE7649BE1B193DEA596E880265F008@SHSMSX101.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1AE640813FDE7649BE1B193DEA596E880265F008@SHSMSX101.ccr.corp.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/22/14 at 05:55am, Zheng, Lv wrote: > Hi, > > I checked the arch/x86/platform/efi/early_printk.c. > In early_efi_scroll_up(), 2 mapping entries will be used for the src/dst screen buffer. > In drivers/acpi/acpica/tbutils.c, we've improved the early table loading code in acpi_tb_parse_root_table(). > We now need 2 mapping entries: > 1. One mapping entry is used for RSDT table mapping. Each RSDT entry contains an address for another ACPI table. > 2. For each entry in RSDP, we need another mapping entry to map the table to perform necessary check/override before installing it. > > When acpi_tb_parse_root_table() prints something through EFI earlyprintk console, we'll have 4 mapping entries used. > The current 4 slots setting of early_ioremap() seems to be too small for such a use case. > > I'm not 100% sure if this is the cause. > If it's the cause and we think both of the mappings are reasonable, we can simply increase the FIX_BITMAPS_SLOTS defined in arch/x86/include/asm/fixmap.h. Hmm, will give see if I can do more debug, I can try what you suggested. Thanks Dave