Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 31 Jul 2002 20:57:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 31 Jul 2002 20:57:50 -0400 Received: from harpo.it.uu.se ([130.238.12.34]:24014 "EHLO harpo.it.uu.se") by vger.kernel.org with ESMTP id ; Wed, 31 Jul 2002 20:57:50 -0400 Date: Thu, 1 Aug 2002 03:01:08 +0200 (MET DST) From: Mikael Pettersson Message-Id: <200208010101.DAA00248@harpo.it.uu.se> To: linux-kernel@vger.kernel.org Subject: Re: 2.5.29: bug in ide and hd kernel option handling Cc: gerald@io.com, martin@dalecki.de Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1877 Lines: 50 On Tue, 30 Jul 2002, I wrote: > On my 486 test box (ISA/VLB only, CONFIG_PCI=n), passing any > any ide or hd kernel option (like idebus=33) to 2.5.29 results > in a kernel hang at boot: I get the initial "Uncompressing .. > booting .." and then nothing. Problem partially identified. With CONFIG_PCI=n, include/asm-i386/ide.h:ide_init_default_hwifs() is defined to ide_register_hw() the PC's standard IDE ports, but with CONFIG_PCI=y, it's empty. When drivers/ide/main.c:ide_setup() is called for some "ide..." kernel option, it starts by calling init_global_data(), which in turn calls ide_init_default_hwifs(). When CONFIG_PCI=n so ide_init_default_hwifs() isn't empty, the kernel either hangs or reboots at that point. init_global_data() and ide_init_default_hwifs() can also be called much later from 'module_init(init_ata)'. In that case there is no hang or reboot -- so my guess is that the initialisation does something which normally works but is illegal and causes a fault when done at __setup()-time. I tested every kernel from 2.5.29 and back, and the problem started with 2.5.5. As a workaround I applied the patch below to unconditionally make ide_init_default_hwifs() do nothing. This solved my problem and doesn't seem to have had any bad side-effects: the kernel still finds all standard IDE ports on my 486. /Mikael --- linux-2.5.29/include/asm-i386/ide.h.~1~ Sat Jul 20 23:49:45 2002 +++ linux-2.5.29/include/asm-i386/ide.h Thu Aug 1 02:20:31 2002 @@ -65,7 +65,7 @@ static __inline__ void ide_init_default_hwifs(void) { -#ifndef CONFIG_PCI +#if 0 && !defined(CONFIG_PCI) hw_regs_t hw; int index; - 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/