From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 25 Jan 2001 10:19:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 25 Jan 2001 10:19:33 -0500 Received: from zeus.kernel.org ([209.10.41.242]:7901 "EHLO zeus.kernel.org") by vger.kernel.org with ESMTP id ; Thu, 25 Jan 2001 10:19:22 -0500 Date: Thu, 25 Jan 2001 15:16:55 +0000 From: "Stephen C. Tweedie" To: Timur Tabi Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: ioremap_nocache problem? Message-ID: <20010125151655.V11607@redhat.com> In-Reply-To: <3A6D5D28.C132D416@sangate.com> <20010123165117Z131182-221+34@kanga.kvack.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2i In-Reply-To: <20010123165117Z131182-221+34@kanga.kvack.org>; from ttabi@interactivesi.com on Tue, Jan 23, 2001 at 10:53:51AM -0600 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Tue, Jan 23, 2001 at 10:53:51AM -0600, Timur Tabi wrote: > > My problem is that it's very easy to map memory with ioremap_nocache, but if > you use iounmap() the un-map it, the entire system will crash. No one has been > able to explain that one to me, either. ioremap*() is only supposed to be used on IO regions or reserved pages. If you haven't marked the pages as reserved, then iounmap will do the wrong thing, so it's up to you to reserve the pages. Cheers, Stephen - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/