From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261446AbULXUpF (ORCPT ); Fri, 24 Dec 2004 15:45:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261447AbULXUpF (ORCPT ); Fri, 24 Dec 2004 15:45:05 -0500 Received: from clock-tower.bc.nu ([81.2.110.250]:8854 "EHLO localhost.localdomain") by vger.kernel.org with ESMTP id S261446AbULXUpB (ORCPT ); Fri, 24 Dec 2004 15:45:01 -0500 Subject: Re: apic and 8254 wraparound ... From: Alan Cox To: Herbert Poetzl Cc: Ingo Molnar , Linux Kernel Mailing List In-Reply-To: <20041224200022.GA14956@mail.13thfloor.at> References: <20041224001144.GA5192@mail.13thfloor.at> <1103845033.15193.6.camel@localhost.localdomain> <20041224200022.GA14956@mail.13thfloor.at> Content-Type: text/plain Content-Transfer-Encoding: 7bit Message-Id: <1103917238.18115.11.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 (1.4.6-2) Date: Fri, 24 Dec 2004 19:40:38 +0000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Gwe, 2004-12-24 at 20:00, Herbert Poetzl wrote: > somehow I'm unable to locate it, I can see the > 430TX and 430HX but not the 430NX and 430LX ... > > do you have an url for me? Not to hand, its under the retired chipset stuff. The details are as follows from memory When you read one 8bit value from an 8254 timer the values latch for read so that when you read the other half of the 16bit value you get the value from the moment of the first read. On neptune that didn't work right so you got halves of two differing samples. That means the error would be worst case a bit under 300 (257 for the wrap + a few for timing)