Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268260AbTGOOsz (ORCPT ); Tue, 15 Jul 2003 10:48:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268276AbTGOOsz (ORCPT ); Tue, 15 Jul 2003 10:48:55 -0400 Received: from firewall.mdc-dayton.com ([12.161.103.180]:57519 "EHLO firewall.mdc-dayton.com") by vger.kernel.org with ESMTP id S268260AbTGOOsy (ORCPT ); Tue, 15 Jul 2003 10:48:54 -0400 From: "Kathy Frazier" To: "Andi Kleen" , Subject: RE: Interrupt doesn't make it to the 8259 on a ASUS P4PE mobo Date: Tue, 15 Jul 2003 11:14:16 -0500 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1254 Lines: 37 Thanks for your reply, Andi. >> We have a proprietary PCI board installed in a (UP) system with an ASUS P4PE >> motherboard (uses Intel 845PE chipset). This system is running Red Hat 9.0 >Have you checked the 845 errata sheets on the Intel website? >Perhaps it is some known hardware bug. >One thing you could try is to use Local APIC / IO APIC interrupt processing >instead of 8259. Our hardware engineer has combed the Intel and ASUS websites, but found nothing. I'll give the APIC a try and see if I get different results and let you know. >> >> /* start timer */ >> dmatimer.expires = jiffies + 0.5*HZ; >That's a serious bug. You cannot use floating point in the kernel. >It will corrupt the FP state of the user process. HZ on the INTEL platform is 100, so this should simply add 50 to the current value of jiffies. Besides, assigning the value to the unsigned int field (expires) will truncate it to an integer anyway. Is there a more appropriate way to handle a short timeout? Thanks, Kathy - 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/