Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755775AbYHTLU6 (ORCPT ); Wed, 20 Aug 2008 07:20:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756123AbYHTLUr (ORCPT ); Wed, 20 Aug 2008 07:20:47 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:40178 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752879AbYHTLUp (ORCPT ); Wed, 20 Aug 2008 07:20:45 -0400 Date: Wed, 20 Aug 2008 13:20:25 +0200 From: Ingo Molnar To: Juergen Beisert Cc: Samuel Sieb , linux-kernel@vger.kernel.org, "Rafael C. de Almeida" , Thomas Gleixner , "H. Peter Anvin" , Magnus Damm , takada Subject: Re: kernel won't boot on a Cyrix MediaGXm (Geode ) Message-ID: <20080820112025.GA24067@elte.hu> References: <48841A92.4020301@sieb.net> <200808201144.02919.jbe@pengutronix.de> <20080820104538.GF2816@elte.hu> <200808201304.00956.jbe@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200808201304.00956.jbe@pengutronix.de> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4695 Lines: 126 * Juergen Beisert wrote: > On Mittwoch, 20. August 2008, Ingo Molnar wrote: > > * Juergen Beisert wrote: > > > On Mittwoch, 20. August 2008, Ingo Molnar wrote: > > > > * Samuel Sieb wrote: > > > > > Ingo Molnar wrote: > > > > >> any patch we should pick up to make your box boot? > > > > > > > > > > I've looked through various datasheets and found that the GXm and > > > > > GXLV Geode processors don't have an incrementor. I attached two > > > > > patches. One only calls the incrementor setup for GX1 or better. The > > > > > other one removes the incrementor setup entirely. As the incrementor > > > > > value differs according to clock speed and we would hope that the > > > > > BIOS configures it correctly, it is probably the better one to > > > > > choose. But I will leave that choice up to you. Either one works > > > > > for me. :-) > > > > > > > > i went for the commit below and queued it up in tip/x86/urgent - thanks > > > > Samuel. > > > > > > > > what happens if the incrementor is not set up correctly by the BIOS > > > > > > The system can freeze. The clock the incrementor modifies is used for > > > the external SDRAM (something like a delay line or jitter reduction). > > > Thats why its setting depends on the core clock speed. > > > > so, what's the recommendation - is the patch fine? (which removes > > incrementor setting, leaving it to the BIOS) > > In my environment I need the incrementor setting in accordance to the > CPU core frequency, as my BIOS sets a wrong value. Removing it is no > solution for me. > > But: There where a few bug reports in the last weeks, and all had > problems when the incrementor setting is changed inside the kernel. > Seems only my BIOS is broken. > > So I vote for removing the incrementor setting. I can life with a > local patch for my kernels. is there any way to specifically identify your board/bios combo, like a DMI string? I have absolutely no problem with adding a quirk for your box. In fact i'd much prefer that solution than you having to carry a local patch - quirks are local only in the rarest of circumstances. Mind doing a quirk patch ontop of the patch below, for us to apply for v2.6.27? Ingo -----------------> >From c6744955d0ec0cb485c28c51eeb7185e260f6172 Mon Sep 17 00:00:00 2001 From: Samuel Sieb Date: Wed, 6 Aug 2008 22:06:29 -0700 Subject: [PATCH] x86: fix "kernel won't boot on a Cyrix MediaGXm (Geode)" Cyrix MediaGXm/Cx5530 Unicorn Revision 1.19.3B has stopped booting starting at v2.6.22. The reason is this commit: > commit f25f64ed5bd3c2932493681bdfdb483ea707da0a > Author: Juergen Beisert > Date: Sun Jul 22 11:12:38 2007 +0200 > > x86: Replace NSC/Cyrix specific chipset access macros by inlined functions. this commit activated a macro which was dormant before due to (buggy) macro side-effects. I've looked through various datasheets and found that the GXm and GXLV Geode processors don't have an incrementor. Remove the incrementor setup entirely. As the incrementor value differs according to clock speed and we would hope that the BIOS configures it correctly, it is probably the right solution. Cc: Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/cyrix.c | 18 ------------------ 1 files changed, 0 insertions(+), 18 deletions(-) diff --git a/arch/x86/kernel/cpu/cyrix.c b/arch/x86/kernel/cpu/cyrix.c index 3fd7a67..e710a21 100644 --- a/arch/x86/kernel/cpu/cyrix.c +++ b/arch/x86/kernel/cpu/cyrix.c @@ -134,23 +134,6 @@ static void __cpuinit set_cx86_memwb(void) setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x14); } -static void __cpuinit set_cx86_inc(void) -{ - unsigned char ccr3; - - printk(KERN_INFO "Enable Incrementor on Cyrix/NSC processor.\n"); - - ccr3 = getCx86(CX86_CCR3); - setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */ - /* PCR1 -- Performance Control */ - /* Incrementor on, whatever that is */ - setCx86(CX86_PCR1, getCx86(CX86_PCR1) | 0x02); - /* PCR0 -- Performance Control */ - /* Incrementor Margin 10 */ - setCx86(CX86_PCR0, getCx86(CX86_PCR0) | 0x04); - setCx86(CX86_CCR3, ccr3); /* disable MAPEN */ -} - /* * Configure later MediaGX and/or Geode processor. */ @@ -174,7 +157,6 @@ static void __cpuinit geode_configure(void) set_cx86_memwb(); set_cx86_reorder(); - set_cx86_inc(); local_irq_restore(flags); } -- 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/