From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 29 Jun 2001 16:40:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 29 Jun 2001 16:40:32 -0400 Received: from hera.cwi.nl ([192.16.191.8]:57504 "EHLO hera.cwi.nl") by vger.kernel.org with ESMTP id ; Fri, 29 Jun 2001 16:40:21 -0400 Date: Fri, 29 Jun 2001 22:40:18 +0200 (MET DST) From: Andries.Brouwer@cwi.nl Message-Id: To: Gunther.Mayer@t-online.de, andre@aslab.com Subject: Re: Patch(2.4.5): Fix PCMCIA ATA/IDE freeze (w/ PCI add-in cards)V3 Cc: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andre Hedrick wrote: > That is a legacy bit from ATA-2 but it is one of those things you cannot > get rid of :-( in ANSI X3.279-1996, "AT Attachment Interface with Extensions (ATA-2)", Approved September 11, 1996 , control register bit 3-7 are reserved. However ANSI X3.221-1994, "AT Attachment Interface for Disk Drives", Approved May 12, 1994, bit3 is "1" and bits 4-7 are "x". No further explanation. How far back must we go, to get the sense ? > struct { > unsigned bit0 : 1; > unsigned nIEN : 1; /* device INTRQ to host */ > unsigned SRST : 1; /* host soft reset bit */ > unsigned bit3 : 1; /* ATA-2 thingy */ > unsigned reserved456 : 3; > unsigned HOB : 1; /* 48-bit address ordering */ > } control_t; > > once I add-in the real def of bit3 then I will not > need to look it up again. bit3: 0: drive has 1-8 heads 1: drive has more than 8 heads (From old MFM/RLL times. In ATA-1 bit3 is set to 1. See also http://www.win.tue.nl/~aeb/linux/hdtypes/hdtypes-2.html .) Andries