Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 24 Jul 2002 18:39:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 24 Jul 2002 18:39:55 -0400 Received: from mion.elka.pw.edu.pl ([194.29.160.35]:8651 "EHLO mion.elka.pw.edu.pl") by vger.kernel.org with ESMTP id ; Wed, 24 Jul 2002 18:39:54 -0400 Date: Thu, 25 Jul 2002 00:42:47 +0200 (MET DST) From: Bartlomiej Zolnierkiewicz To: Pete Zaitcev cc: Bill Davidsen , Subject: Re: Safety of IRQ during i/o In-Reply-To: <200207242237.g6OMbSO10262@devserv.devel.redhat.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 996 Lines: 31 On Wed, 24 Jul 2002, Pete Zaitcev wrote: > >[...] > > I would think that this would be safe when using DMA, and likely to be > > safe for PIO and more recent chipsets, but I wouldn't want to actually > > tell anyone that. > > A little story from OLS. I have a 486/75 laptop, which can only > do PIO. It always was losing characters evern on 9600 baud on its > serial port, and I thought it was simply broken for five years. :-) > A guy who did a security talk showed me that doing hdparm -u > fixes the problem. Apparently, the lappy has a non-buffering UART. > > So, it seems that hdparm -u is a very useful thing for obsotele > boxes. If you do DMA, you probably do not care. Yup, for PIO unmask (if possible) is a must. --bzolnier > -- Pete - 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/