Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763303AbXIZVVS (ORCPT ); Wed, 26 Sep 2007 17:21:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755633AbXIZVVF (ORCPT ); Wed, 26 Sep 2007 17:21:05 -0400 Received: from terminus.zytor.com ([198.137.202.10]:58658 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752092AbXIZVVB (ORCPT ); Wed, 26 Sep 2007 17:21:01 -0400 Message-ID: <46FACD33.1050503@zytor.com> Date: Wed, 26 Sep 2007 14:20:51 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.0 (X11/20070419) MIME-Version: 1.0 To: Jordan Crouse CC: Joerg Pommnitz , cebbert@redhat.com, linux-kernel@vger.kernel.org Subject: Re: Regression in 2.6.23-pre Was: Problems with 2.6.23-rc6 on AMD Geode LX800 References: <637040.99806.qm@web51411.mail.re2.yahoo.com> <46FA6858.5060908@zytor.com> <20070926154106.GG7582@cosmic.amd.com> <46FAAFA7.50106@zytor.com> <20070926205825.GA14877@cosmic.amd.com> <46FAC958.9000501@zytor.com> <20070926211558.GB14877@cosmic.amd.com> In-Reply-To: <20070926211558.GB14877@cosmic.amd.com> X-Enigmail-Version: 0.95.0 Content-Type: multipart/mixed; boundary="------------050302030300010407030402" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3530 Lines: 123 This is a multi-part message in MIME format. --------------050302030300010407030402 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Jordan Crouse wrote: > > Hmm - the old code seems to fail to e801 when CF was set too: > > int $0x15 # make the call > jc bail820 # fall to e801 if it fails > > cmpl $SMAP, %eax # check the return is `SMAP' > jne bail820 # fall to e801 if it fails > > Thats not to say that the old code was correct, mind you. Failing on a > bad ID and returning without error on a set CF seems to be good to me. > Testing this patch now: --------------050302030300010407030402 Content-Type: text/x-patch; name="0001-x86-setup-Handle-case-of-improperly-terminated-E82.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename*0="0001-x86-setup-Handle-case-of-improperly-terminated-E82.patc"; filename*1="h" >From 2efa33f81ef56e7700c09a3d8a881c96692149e5 Mon Sep 17 00:00:00 2001 From: H. Peter Anvin Date: Wed, 26 Sep 2007 14:11:43 -0700 Subject: [PATCH] [x86 setup] Handle case of improperly terminated E820 chain At least one system (a Geode system with a Digital Logic BIOS) has been found which suddenly stops reporting the SMAP signature when reading the E820 memory chain. We can't know what, exactly, broke in the BIOS, so if we detect this situation, declare the E820 data unusable and fall back to E801. Also, revert to original behavior of always probing all memory methods; that way all the memory information is available to the kernel. Signed-off-by: H. Peter Anvin Cc: Jordan Crouse Cc: Joerg Pommnitz --- arch/i386/boot/memory.c | 30 +++++++++++++++++++++++------- 1 files changed, 23 insertions(+), 7 deletions(-) diff --git a/arch/i386/boot/memory.c b/arch/i386/boot/memory.c index 1a2e62d..bccaa1c 100644 --- a/arch/i386/boot/memory.c +++ b/arch/i386/boot/memory.c @@ -20,6 +20,7 @@ static int detect_memory_e820(void) { + int count = 0; u32 next = 0; u32 size, id; u8 err; @@ -33,14 +34,24 @@ static int detect_memory_e820(void) "=m" (*desc) : "D" (desc), "a" (0xe820)); - if (err || id != SMAP) + /* Some BIOSes stop returning SMAP in the middle of + the search loop. We don't know exactly how the BIOS + screwed up the map at that point, we might have a + partial map, the full map, or complete garbage, so + just return failure. */ + if (id != SMAP) { + count = 0; break; + } - boot_params.e820_entries++; + if (err) + break; + + count++; desc++; - } while (next && boot_params.e820_entries < E820MAX); + } while (next && count < E820MAX); - return boot_params.e820_entries; + return boot_params.e820_entries = count; } static int detect_memory_e801(void) @@ -89,11 +100,16 @@ static int detect_memory_88(void) int detect_memory(void) { + int err = -1; + if (detect_memory_e820() > 0) - return 0; + err = 0; if (!detect_memory_e801()) - return 0; + err = 0; + + if (!detect_memory_88()) + err = 0; - return detect_memory_88(); + return err; } -- 1.5.3.1 --------------050302030300010407030402-- - 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/